Heating boiler backflow preventer valves (BBFP) FAQs.

This article series describes backflow preventers used on heating boilers including their function, location or placement, and their troubleshooting and repair of leaks or other problems.

Heating Boiler Backflow Preventer Valves [BBPF] FAQs

These questions and answers about boiler backflow preventers were posted originally at BACKFLOW PREVENTER VALVE, HEATING SYS - you will want to review the explanation and types of valves and diagnostic suggestions there.

Heating boiler backflow preventer valves protect public water mains as well as private building water piping from heating system water contaminants.

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On 2018-05-10 by (mod) - backflow valve is leaking at the relief port

I am guessing that your backflow valve is leaking at the relief port, not one of its plumbing connections.

If that's so, and IF your piping system never suffers from water hammer (that can cause such valves to leak), THEN debris could have jammed the valve's internal closure port - I would replace the valve.

On 2018-05-09 by Brian

My back flow valve on the boiler is constantly leaking ....currently have no running around water or pressure....well pump pressure at zero ...any thoughts?

On 2017-06-22 by (mod) - can I replace my 1/2 in. backflow valve with 3/4 backflow valve

Yes

On 2017-06-21 by ron

can I replace my 1/2 in. backflow valve with 3/4 backflow valve on my hot water furnace ?

On 2017-02-02 by Curt

Opened and closed thumb screw a couple of times and it's working correctly at this time

On 2017-02-02 16:00:51.326380 by Curt

New two zone forced hot water heating system has had taco #219 flo-chek replaced on one zone and new valve is leaking after a couple of weeks allowing hot water into zone (first seemed to last a few weeks also) taco said to clean the seat maybe it got solder or flux on it, can you describe the necessary steps for this job
Thanks curt

On 2016-12-30 21:39:55.885005 by (mod) -

Paula

A "tankless coil" in a home heating boiler, used to make hot water for washing and bathing - is described and explained at https://inspectapedia.com/plumbing/Tankless_Coil_Guide.php

You'll see that the amount of hot water (volume) is rather limited. You can make the water a bit hotter by either setting the boiler temperature controls up a bit

(search InspectApedia.com for AQUASTAT SETTINGS)

or by slowing down the flow-rate of water through the tankless coil - that'll let the water absorb more heat from the water. You probably won't get a long hot shower unless you install a different means of making hot water in winter

(search InspectApedia.com for MORE HOT WATER).

On 2016-12-29 21:03:58.374898 by Paula

i have an oil fired hot water heating boiler or i think also referred to as a tankless boiler?
In the winter months only, and it has just started this winter..

.i have very little hot water in my shower only. All the household sinks run hot water right away.

On the highest setting in the shower, you are lucky to get luke warm water. In the summer, the water is scolding hot. I replaced the guts of the faucet with a low flow or reduced flow part recommended by the manufacturer already so i dont think that is the problem. Wondering if you have any suggestions. Thank you.

On 2016-03-19 20:51:06.786208 by (mod) -

I'm not sure what's going on, Anon as I don't know where on the boiler the leak is occurring. Take a closer look.

On 2016-03-19 16:10:28.486722 by Anonymous

I turned the main water valve off to work on the tub valve, but I didn't shut off the valve to the supply on the boiler.

When I came back into the basement to turn the main valve on the back flow valve on the boiler was leaking and still is what do I do now????

On 2016-01-03 16:44:23.157660 by (mod) -

Rose,

I have not found reports of a failure of a backflow preventer to pass water on through to the system except in cases where it was installed backwards, but I suppose it's possible.

When I read manufacturer's description of backflow preventer valve failures and testing procedures, the discussion attends water discharge from a relief valve port on the backflow preventer valve and it attends failure of the first or second check valve components that reduce pressure across the valve.

The effect of a failure in the check valves would be an increase in system pressure on the downstream or boiler side of the valve, not a failure to pass water.

There are of course various models and applications for backflow preventers that include other features such as a backflow preventer designed to always pass water at the first few psi of demand to assure water feed to a fire sprinkler system, and SVB versions of backflow preventers that include a shutoff feature; none of these are likely to be found on most residential h eating systems.

So I'd start by investigating the condition of the water feeder valve, or first testing its pressure bypass lever feature if your valve includes that component.

On 2016-01-02 01:06:21.897976 by Rose

Can a faulty backflow prevention valve block water from entering the feeder valve and subsequently, into the boiler? No water is flowing through the feeder valve after we bled the baseboard heaters.

On 2015-12-24 22:26:48.190904 by (mod) -

Sonny

I expect your service tech will look for a failing or debris-clogged check valve, or less likely an overpressure condition due to a water feed problem or other overpressure cause.

On 2015-12-24 03:04:35.573343 by Sonny

Why is water backing up from the boiler supply feed and leaking out of the dual check valve vent

On 2015-09-15 01:49:45.195276 by Michelle

Thanks! Will do

On 2015-09-15 01:41:49.841910 by (mod) -

It sounds as if there is over pressure, a water hammer problem, or a failed backflow preventer - maybe debris clogged. Yes call the plumber.

On 2015-09-15 00:17:57.324417 by Michelle

2 days ago we had to turn off the water in our home to perform a plumbing repair. We turned the water back on without incident. A little over 30 hours later, the backflow preventer is now leaking, probably releasing a full bucket of water and still going. Is this normal or should we get our plumber over to look at it?

On 2015-08-25 15:27:13.404322 by (mod) -

Mark:

at https://inspectapedia.com/heat/Aquastat_Settings.php you'll see information about how your boiler aquastat control is set; yours may be set to keep heat in the boiler during summer as if there were a tankless coil in use for domestic hot water.

On 2015-08-25 02:57:34.824130 by Mark

Hot water furnace cycles during off season. Heats home when t stat is not calling for heat. disconnected t stat and furnace still cycles.

On 2015-08-08 19:26:32.005223 by (mod) -

You're good to go.

On 2015-08-08 14:19:49.460760 by Anonymous

Thanks for the prompt reply. yes there is a shut off valve before the back flow preventer and the water pressure reducer is after the BFP

On 2015-07-31 13:33:56.392570 by (mod) -

You can if there is a shutoff valve between boiler and the water supply.

On 2015-07-31 10:26:19.015676 by clem zahrobsky

can I change my back flow preventer on my boiler without draining the whole system ??? THANKS

On 2015-06-15 16:08:51.381710 by (mod) -

Marc: it sounds as if your boiler Flo-Control valve is open or stuck open. See

https://inspectapedia.com/heat/Check_Valves_Heat.htm

for details.

On 2015-06-15 15:48:52.896380 by marc

even with the thermostat off, I get heat circulating through the baseboards. I have an oil fired boiler and domestic hot water is made through the boiler, so if shut the boiler off, I have no hot water. what is the cause and what is the cure? thanks,Marc

On 2014-08-08 19:40:57.956410 by Christina

Thank You

On 2014-08-08 16:33:03.485700 by (mod) -

Christina

I've not come across research nor field experience that associates heavy rainfall with falling municipal water pressure, though I could SPECULATE that flooding could of course impact pumps, wells, or water delivery systems in general.

On 2014-08-08 02:22:22.008670 by Christina

Can a heavy rain drop municipal water supply pressure down enough to draw water/air back from boiler water to house supply water when there is no or faulty check valve?

Can addition of above check valve solve such a problem if it is possible? I get air in my pipes seemingly only after heavy rains. This website seems to be my only hope. Boiler system frequently air bound….no cold sections but a lot of water flowing sounds.

...

Continue reading at BACKFLOW PREVENTER VALVE, HEATING SYS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

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