Recent FAQs about water feeder valves on steam heating boilers - set 2.

Diagnostic, repair & maintenance questions and answers about the various types of manual and automatic water feeder valves used on steam heating boilers.

Troubleshoot & Fix Steam Boiler Water Feeder Valves

 Recent questions & answers about steam boiler water feeders & LWCOs originally posted at WATER FEEDER VALVE, STEAM - home. You will want to review the water feeder control diagnosis and repair advice given there.

On 2018-10-26 by (mod) - can you shut off the water feed to the boiler?

Hydronic heating systems and even a steam boiler can run for a time with the water feed shut off.

Watch out: However particularly be with a steam heating system, because Steam Heat always consumes some water, if you don't have an automatic or regular manual water feed to the boiler the heating system, if it's working properly, will simply shut down when the water level in the boiler becomes low - that is you will have no heat.

Watch out: More serious, if the heating boiler does not have a low water cutoff safety control and the boiler Runs Out of Water the boiler could become damaged, destroyed, or even explode.

On 2018-10-26 by (mod) - will a boiler run with water shut off?

Hydronic heating systems and even a steam boiler can run for a time with the water feed shut off.

However particularly be with a steam heating system, because Steam Heat always consumes some water, if you don't have an automatic or regular manual water feed to the boiler the heating system, if it's working properly, will simply shut down when the water level in the boiler becomes low - that is you will have no heat.

Watch out: More serious, if the heating boiler does not have a low water cutoff safety control and the boiler Runs Out of Water the boiler could become damaged, destroyed, or even explode.

On 2018-10-26 by Anonymous

Can you run the furnace with your water being shut off?

On 2018-06-05 by (mod) - I emptied my steam boiler for summer but it filled back up.

I'm not familiar with a requirement to empty a steam boiler when it is shut down in the summer.

But an automatic water feed valve will simply re-fill the boiler automagically.

In any case to turn off the water feeder you would turn off the water supply into the water feeder and also if it's a powered unit you would disconnect its electrical power source.

Watch out: some boilers, particularly some older cast-iron models, may develop leaks if left empty.

On 2018-06-05 by Denise

I apologize for my type-o's. I emptied my steam boiler for summer but it filled back up. I am guessing that I need to turn off auto-fill but I don't know where or how. Thank you.

On 2018-06-05 by (mod) - how do I turn off an automatic water feeder?

Remove power to the device

You can also turn off the boiler's water supply.

Watch out: doing so is unsafe if you turn the boiler's burner on before the boiler is re-filled.

On 2018-06-05 by Denise

Hiw do you shut off auto feed on steam boiler for sommer when you drain it

On 2018-02-13 by (mod) -An automatic water feeder saves you trouble and increases the reliability of your heating system.

Judy

An automatic water feeder saves you trouble and increases the reliability of your heating system. There are several residential steam boiler water feeders and level controllers. CHeck the requirements for periodic manual cleaning (flushing of the water feeder) as that may vary among designs.

Please ask your plumbers to be very specific about why they recommend against an automatic water feeder on a residential steam boiler. I'd like to learn from their experience and to report that to others.

Their argument might be that it's better to force the homeowner to make a regular inspection of conditions at the boiler, or they may have had a problem with improperly-installed or improperly-maintained controls that flooded the steam boiler (there are excellent devices designed to prevent boiler flooding)

However a problem with boiler flooding ends at the same place (loss of heat) as a steam boiler into which the homeowner forgets to manually add water when needed (possibly daily during very cold weather) and also the same as a boiler whose low-water cutoff (LWCO) safety device is not maintained by the homeowner (regular flushing) - also leading to loss of heat or worse, a damaged boiler.

If you're worried about boiler flooding or boiler running out of water regardless, there are reliable add-on devices that sense and protect against that- discussed in the article above on this page.

But I would certainly use a plumber who has had successful water feeder installations to do the job. I worry that a contractor who condemns such as common and widely used heating system control may have had bad experience not because the control is defective but because she has repeatedly not followed the proper installation or maintenance instructions given by the manufacturer.

On a rainy day I inspected a new home whose gutters were all spilling over, pouring water along the house foundation.

The builder was there.
I asked him if he'd noticed that none of the guitters were working and all were spilling over instead of conducting roof drainage away from the building.

"Yeah," he said, "That's normal. They all do that".

On a closer look I saw that the roof edge flashing was improperly installed, directing roof runoff behind the gutters rather than into them.

So yeah, all of the gutters that HE installs do spill where they shouldn't.

On 2018-02-13 by Judy - My boiler died and I need to replace it.

My boiler died and I need to replace it. I chose a Burman boiler. I have steam heat operated by oil. I wanted to put in an automatic water feeder but I am having second & third thoughts about it.

I have read where it can cause flooding both upstairs and downstairs and 2 plumbers did not recommend the automatic water feeder.

Any thouighhts or help?

On 2018-02-11 by (mod) -

Sharon

An automatic water feeder is not, using my subjective opinion, normally loud. So if you're hearing unusually loud noises there could be a clog or other problem with your water feeding device - a good question to bring to your heating service tech to see what she has to say.

On 2018-02-11 by sharon

Why is the automatic water feeder so loud

On 2018-02-08 by (mod) -

Jerry

I think that's quite possible provided that you install a suitable power transformer as needed to power the 24VAC VXT. Before buying the water feeder give Hydrolevel a call and ask for hookup advice 800-654-0768

On 2018-02-08 by jerry thibault

Is it possible to install a VXT-24 auto water feeder on a residential millivolt steam boiler?

The millivolt steam boiler has no incoming power source connection because the burner and controls circuit is 750 millivolts (less than 1 volt) and is powered by the power pile generator above the pilot light.

If the boiler goes into emergency low water cut-off, the millivolt circuit does not have enough power to operate and open the water feed solenoid valve on the VXT-24 because that valve needs 24 volts to operate.Is there a type of relay control available the receives the millivolt low water signal and converts it to 24 volts to operate the feeder?

On 2018-01-14 by (mod) -

Ronald

An automatic water feeder that does not feed is often debris clogged due to lack of regular flush-out maintenance.

But
You should not have to be feeding water to a steam boiler every half-hour. That sounds as if there is a leak somewhere in the system. Or the boiler is not being filled to the proper level. I would call for repair.

On 2018-01-14 by ronald.lee

My steam boiler water feeder isn't working. I have to go down and fill it manually, then 30-40 min later go and fill it again. I had the whole thing fix a month ago. Everything was working now I have to do it myself

On 2018-01-06 by Anonymous

No panic needed.

Here are safety highlights

If the boiler is keeping tthe house warm,

and if the water feeder is keeping water in the boiler,

And if the relief valve is not dumping water,

And you don't see smoke or soot,

Then one more step would be Insurance of your safety,

Working smoke and carbon monoxide detectors properly located in sleeping areas and near the boiler.

On 2018-01-05 by Anne

I called the plumbers who worked on my system and they cannot come until Tuesday morning. We are in a deep freeze in New England and everyone's backed up. This has been happening since Thanksgiving when the auto feeder was replaced in November,

but my gut kept telling me it wasn't right. Do you think it's the type of thing where i'm in danger sleeping here or something that can wait till they arrive on Tuesday?

On 2018-01-05 by (mod) -

Look first for a boiler leak into the combustion chamber

On 2018-01-05 by Anne

Hi. Exasperated. Decent Burnham steam boiler with auto water feeder. Auto water feeder stopped working. Plumber came out and replaced. Since it was replaced, the water level is not as high as it was before and fills every hour. Before it stayed towards the top and filled only about once/day.

There is also a lot of thick white smoke coming from chimney, which I don't recall before. I do have heat. Just worried about the number of times the water feeder turns on. Do I need to be worried? I don't think this means anything, but at same time, creosote started leaking into basement from a metal door.

Chimney guy says I have a ripped liner and he's replacing on 1/22. Just thought it was odd this all happened at once.

I only use furnace, not fireplace. Would love for you to tell me it's normal when it's this could out (it's really cold) for water to fill every hour. Thanks for your help....from a woman worrying about this by herself. 0 :

On 2017-12-31 by (mod) -

Steve

Companies making boiler water feeders assume that their equipment is being installed by a plumber or heating technician and they assume the tech knows to connect the boiler feed water to the building's cold water supply.

But your are mistaken in assuming that the manufacturers do not specify how the water feeder should be connected.

In the live links above you will find this example

McDonnell & Miller ITT Series 47 & 247 Mechanical Water Feeders, Series 47-2 & 247-2 Combination Mechanical Water Feeder & Low Water Cut-Off

wherein the company tells us in bold font right at the top of the installation instructions:

Application:

For steam and hot water boilers with cold water feed, to maintain a minimum safe water level independent of electrical service.

I agree that it is difficult for a manufacturer to anticipate all possible snafus involving their equipment. But in this case those instructions are clear.

For other readers:

NEVER connect a heating boiler's water supply from the building hot water piping. All of the boiler controls, such as automatic water feeders assume a cold water feed. That's because feeding in hot water starts the boiler at a higher temperature that in turn risks over-pressure conditions and leaks at a relief valve when the boiler's burner operates.

On 2017-12-31 17:44:33.656500 by Steve

Not one of these companies not one of them tell you whether the automatic water feed is connected to the cold or hot water now one company tells you in writing . The water pipe in the PDF is labeled water supply . After your house floods and your insurance adjuster comes out and tells you it can’t be connected to the hot water you realize why . Why don’t they sat which water supply it belongs connected to ?

On 2017-10-10 by (mod) - causes and cures for steam boiler not getting enough water

William

The McDonnell Miller Series 47-2/247-2 Mechanical Water Feeder/LWCO is a mechanical (not electronic) control that uses a moving float arm to sense water level.

I look first for a debris-clog that is jamming a float. The following diagnostics are quoted from the I&O Manual for this control, available from

McDonnell & Miller and also as a free download at our article LOW WATER CUTOFF VALVE
at https://inspectapedia.com/heat/LWCO_Low_Water_Cutoff_Control.php#LWCOManuals

Boiler is not getting enough water.

a) Cause: There is something preventing the valve (cartridge poppet) from fully opening.

Test: Perform broken union test.

Solution: Remove and inspect cartridge. Clean or replace as necessary.

b) Cause: Strainer clogged with sediment.

Test: Perform broken union test.

Solution: Remove and inspect strainer. Clean or replace as necessary.

c) Cause: Float chamber clogged with sediment.

Test: Open blow-down valve. If there is little or no water flow, the chamber may be clogged with sediment.

Solution: Remove bottom of float chamber and clean sediment from chamber, float and bellows mechanism. Replace control if necessary.

d) Cause: Feed line between valve and boiler is partially plugged.

Test: Perform broken union test. With union broken, there should be water flowing through the piping from the boiler.

Solution: Clean or replace piping. e) Cause: Feed line between valve and city water supply is plugged. Solution: Clean or replace piping.

f) Cause: Water supply pressure is less than boiler pressure.

Solution: Reduce boiler pressure or convert to pumped return.

On 2017-10-09 by William McCrea - will not automatically refill as the water level drops

I have a Mcdonald Miller control on a small steam boiler - the low water cut off works but it will not automatically refill as the water level drops - Is this a float valve problem or is it electronic? - the MM sn is 204835 - the MM control is N'47-2, 2 switch model 2

On 2017-08-29 by (mod) - Auto Feeder Box is flashing,

Yes that is a concern, because you have to keep adequate water in the boiler to protect it from being damaged.

Or there will be a low water cutoff control which, if it is working, we'll turn off the boiler. First check the water level to be sure it is at the proper line marked behind the sight glass. If the water is below the safe level it would be best to turn off the boiler. In any case you need to call for repair.

On 2017-08-27 by Marie

Auto Feeder Box is flashing, I don't think that it is working, should I be concerned?

On 2017-04-14 by (mod) -

Rodney, I'm confused.

A hot water heater (or calorifier, geyser, cylinder, depending on where you live) is a device to produce domestic hot water for washing and bathing.

Water is fed INTO a water heater from the building's cold water supply - there wouldn't be an automatic water feeder: those are used, as you'll read in the article above, on boilers used to heat the building itself, usually steam boilers since those do consume water in normal operation.

Start by following the hot water pipes from the water heater outlet side: look for a shutoff valve that was left closed.

On 2017-04-14 18:40:16.098105 by Rodney

Got a hot water heater installed the plumber put the automatic water feeder in the hot water line now we have no hot water up stairs

On 2017-02-18 by (mod) -

Sam, that's a good question.

McDonnell Douglas says that using an electronic automagic water feeder with a McDonnell Douglas Series 700 LWCO manual-reset model can lead to flooding of the steam boiler - that is, the water feeder may over-fill the boiler.

See this ITT McDonnell Miller LWCO manual for details

https://inspectapedia.com/heat/ITT-McDonnell-Miller-PS-802-852-Water-LWCO-Manual.pdf

On 2017-02-18 by Sam

I just bought a McDonnell Douglas series 800 probe low water cut off manual reset model and it says do not use with electronic automatic water feeder's do you know why

On 2017-01-13 by (mod)

Sorry Chris I'm a bit confused about what equipment and valves we're discussing.

Typically we use the word "boiler" to refer to a water filled heating device that is used for building heating - making hot water that circulates through baseboards or radiators, or making steam that circulates to steam radiators.

A "water heater" is in simplest case, a physically separate heating device that makes hot water for washing and bathing.

If a valve is leaky or broken often it can be replaced, but if the heater is old and badly rusted or corroded it might be that the tapping into which the control valve screws is so damaged, rusted, corroded - making it impossible to remove the old valve without damage to the heater or making it impossible to screw in a new valve to a successful seal: that repair is not economical.

There are some hybrid systems that you can read about by searching InspectApedia for

TANKLESS COIL HOT WATEr

INDIRECTE FIRED WATER HEATEr

RANGE BOILER HOT WATER

On 2017-01-13 by Chris - McDonnell Boiler Control 25psi 47-2.

Hi again, is the water heater valve part of the boiler control I have a McDonnell Boiler Control 25psi 47-2.

Would the valve be in this, if so can it be repaired or should the whole unit just be replaced? thanks for the help Chris

On 2017-01-13 by (mod)

This sounds to me as if your water heater valve is not working correctly and needs repair or replacement.

On 2017-01-13 by Chris - Is there a way to adjust the level on the water feed to keep it in the middle?

My boiler water level has just started raising and the whole system is knocking, etc. I flushed out the system and refilled the boiler but it keeps going way past the usual spot about half way up the glass display on the side to about the top of the display.

Is there a way to adjust the level on the water feed to keep it in the middle? I figure something must have broke since this just started happening along with excessive steam from the radiators. thank you

On 2017-01-10 by (mod) - Is it normal to have to add water to water tube on furnace when it is very cold outside

Joan:

In a sense, yes.

It is normal for steam heating boilers to consume some water at each heating cycle. That's because even in a steam heating system in perfect operating condition, some water is lost in the form of steam at steam vents at each radiator at the start of each heating cycle.

Rising steam pushes out air in cold radiators, forcing the air out through a thermostatically operated steam vent on each radiator. At the end of that "force the air out" portion of the heating cycle a bit of steam escapes along with escaping steam before the steam vent closes.

And some steam heat systems whose steam vents are not working perfectly may continue to let steam (and thus water) escape longer into or even all during the heating cycle.

So in sum, part 1, all steam heat systems use some water each time the system goes through a heat-on cycle.

Now in cold weather a steam boiler will run more often, as the house is losing heat faster, so it needs more heat from the steam heating system.

When steam heat runs more often, more water is consumed or "lost".

When more water is lost, make-up water will have to be added to the steam boiler more-often.

You are not adding water just to the "water tube" (search InspectApedia.com for STEAM BOILER SIGHT GLASS for details)
You are adding water to the steam boiler itself.

If your steam boiler has an automatic water feeder valve it will do this for you.

If your steam boiler's automatic water feed valve is not working it's time to call for service and repair. Failing to do so can damage the steam boiler.

Watch out: also in times of frequent on-off cycling of the steam boiler its low water cutoff valve, a critical safety device, will need to be flushed or cleaned more-often. Search InspectApedia for STEAM BOILER LOW WATER CUTOFF VALVE for details.

On 2017-01-10 by Joan

Is it normal to have to add water to water tube on furnace when it is very cold out

On 2016-09-27 by (mod)

Tess:

Please see details about the VXT at WATER FEEDER VALVE, VXT-24 FAQs - https://InspectAPedia.com/heat/VX-24_Steam_Boiler_Water_Feeder_FAQs.php

On 2016-09-27 by tess

I have a vxt automatic water feeder that won't shut off amd keeps humming. The readout sais L90..from what I've read there arethings I can do to troubleshoot before calling a repair man.What do you think it means and how do I do this?

Question: how does the automatic water feeder add makeup water to a steam boiler

Does the automatic water feeder on the steam boiler add water slowly to the boiler and if you have to add water manually should you add slowly when the boiler is not running. - Mary Jo Barranco

Reply:

Mary Jo:

If your steam boiler has an automatic water feeder it will add water whenever the level drops enough to drop the float in the sensor. It doesn't feed water continuously.

The water feeder will add water frequently enough, and in small enough doses, and at a slow enough rate that even if the boiler is hot the makeup water won't damage the equipment.

You can take a look at the water level in the boiler by noting the sight gauge - that vertical glass tube.

There may already be a normal water level mark - if not, just put one on with a magic marker. If you should see the water level in the boiler fall say half way between that mark and the bottom of the sight glass, then I suspect the auto water feeder isn't. Otherwise it should come on by itself and restore water to the boiler as needed.

Question: how to diagnose frequent on-cycling of automatic water feeder on boiler; initial dwell? dip switch settings?

My new steam boiler has an auto feeder that cycles on frequently, even when the boiler has been off for hours, such as overnight. Is that normal? I am considering changing the DIP switches to change the dwell/feed but need your advice. Can you tell me if increasing the feed time would add more time between cycles?

What does "initial dwell" refer to? There is no marker on the sight glass but the water generally lays at one third the twelve inch glass. I think that is low but even if I add water manually, that level is maintained after a while. - Bob Q from Brooklyn

Reply: look for a leak in the steam piping, particularly the condensate piping, or possibly improperly functioning steam vents

Bob Q,

When a steam boiler is and has been cold for a while no water should be leaving the boiler, and therefore I wouldn't expect the auto water feeder to cycle on. Even though your steam boiler is new, it's likely that your steam piping, condensate return lines, etc. are not. I'd look for a leak around the boiler itself.

You can miss a small boiler piping leak when the pipes are hot because the leaking water just evaporates. Check carefully when the system has been cold and off for a few hours or more.

I understand the temptation to adjust the automatic water feeder, but those adjustments wouldn't be expected to make the device feed water when the system has been off and cold.

When you feed extra water to the boiler it will eventually be consumed (steam losses in the system - all steam systems consume some water) and since you fed it manually, the system will naturally return to the water level being maintained by the automatic water feeder.

About whether or not the set level of water is too low, look on the boiler itself - many of them have a "water level" line marked or riveted on the boiler side by the manufacturer.

If you send me (use the CONTACT link on our pages) the brand and model of your water feeder I'll dig up the instructions to see what further advice we can offer.

...

Continue reading at WATER FEEDER VALVE, STEAM - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see WATER FEEDER VALVE, STEAM FAQs-3 - more recent questions and answers about water feeders on steam boilers

Or see these

Recommended Articles

• LOW WATER CUTOFF VALVE
• LOW WATER CUTOFF VALVE NOT WORKING
• STEAM BOILER FLOODING / SURGING REPAIR where we explain the causes of water too high in the sight glass or in the steam boiler
• STEAM BOILER SIGHT GLASS
• STEAM BOILER WATER FEEDER VALVE MANUALS
• STEAM HEATING SYSTEMS & CONTROLS - home
• WATER FEEDER VALVE, HYDRONIC BOILER

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