Older Heating Boiler Repair FAQs #3

Boiler conversions, efficiency, odors,
No heat upstairs but get heat on lower floors

Hydronic Heating Boiler Efficiency FAQs

How efficient is a hot water heating boiler?

I just looked at a home to buy that has hot water boiler heat. Don't know age but owners say they have always had it maintained since he is a plumber.

Are we crazy to consider a house with this type of heating system. How energy efficient are they? On 2014-04-13 by Diane Logsdon -

Reply by (mod)

The efficiency of a hot water heating boiler depends on the age and type of boiler, its fuel, and most important, how properly it has been serviced, including cleaning, adjusting, and tuning for proper operation.

A new condensing boiler may have an efficiency in the 90s while an oil boiler that's dirty and un-tuned could be as low as in the 60-70% range.

To better understand heater energy efficiency take a look at

AFUE DEFINITION, RATINGS 

and when you are in your new home, be sure to review

ENERGY SAVINGS PRIORITIES

Heating Boiler Odor FAQs

Burning smell when boiler first turns on

My heating boiler had a pretty heavy burning smell for about 5 minutes when the heat kicked on (we're in NY so its been on for the past 5 months).

My husband and I could not find anything but now when the whole system kicks on and ignites it sounds like we have an open blow tourch in our basement.

No smell anymore but frankly I am worried.

Our system is approximately 45 years old. On 2014-03-18 by Mary Rubin -

Reply by (mod) - your heater may be unsafe - look first for a chimney fire or similar hazard

Mary from your message alone I can't guess at what's wrong but what considering the potential risks involved I have to give advice that errs onthe "safe side":

Watch out: what you describe does not sound safe.

If it were my system and there were sudden odors, smoke, or loud roaring noises (which could be a dangerous chimney fire) I would shut the system off and call the heating company for emergency service.

Watch out: If you suspected a chimney fire (look outside at the chimney top for dense smoke or flame) call the fire department and get out of the house.

Detailed help is at

HVAC SYSTEM ODORS

and if your boiler uses an oil burner

see OIL BURNER NOISE SMOKE ODORS - home

No Heat Upstairs FAQs

What can I do to get the heat to rise up to the first floor?

What can I do to get the heat to rise up to the first floor because the heat is coming up in the basement ? On 2014-01-25 by gwen

Reply by (mod) -

Gwen, we would need to know a bit more about your heating system to even venture a wild arm-waving guess. Is this forced warm air, hot water heat, baseboards? radiators? Steam heat?

Depending on the type of heating system one would be looking for different problems.

For example if your heat is forced hot water baseboards or radiators and you have heat on some floors but not others, I'd look for a stuck zone valve, a thermostat not working properly, or an air-bound heating zone.

But if the heat is forced warm air I'd look for closed registers, crimped or disconnected heating ducts, or a zone damper not working.

Detailed help is at

How to Fix No heat upstairs: hot water heat

See these articles

CIRCULATOR DIAGNOSTICS - if the too-cold zone has its own circulator, the circulator may not be running or may be damaged

ZONE VALVES, HEATING - home - if the too-cold zone has its own zone valve, the zone valve may not be opening fully

AIRBOUND HEAT SYSTEM REPAIR - partial air blockage means delivery of heat to a zone is impeded or reduced but not necessarily stopped completely

HEAT INSUFFICIENT or UNEVEN - more complete explanation of causes of uneven heat delivery in a building

THERMOSTAT SETTING INSTRUCTIONS - How to Set the Thermostat

How to Fix No heat upstairs: warm air heat

See these diagnosis and repair articles

AIR FLOW IMPROVEMENT, HVAC

BALANCING AIR DUCT FLOW

DIAGNOSE & FIX FURNACE PROBLEMS 

HEAT INSUFFICIENT or UNEVEN - more complete explanation of causes of uneven heat delivery in a building

TEMPERATURE RESPONSE of ROOM THERMOSTATS

No heat on second floor

My boiler heat works fine on my first floor but I have no heat on my second floor.

If I continue to bleed the farthest line it gots hot but as soon as I shut the bleeder off it gets cold again.

Could it be that my pump is not large enough to push the water thru to the second floor? Any comments are appreciated On 2017-10-27 by Joe

Reply by (mod) -

Joe,

If previously you had heat on the Upper Floor then unless something has happened to the circulator pump I wouldn't suspect that it's a circulator capacity.

More likely you haven't been able to successfully bleed the air out of an air bound system.

Keep in mind that an air blockage in an airbound heating system can be in a section of pipe well ahead of those cold radiators.

AIRBOUND HEAT SYSTEM REPAIR - may solve this problem. Be sure that the boiler is up to full operating temperature and pressure before trying to bleed air from the upstairs zone.

Diagnose why my upstairs steam heat radiator stays cold

I have a gas boiler steam heater. The second floor radiator in the bedroom is cold, but the radiator in the living room has heat.

What can I do to fix this? On 2018-11-04 by Anonymous

Reply by (mod) -

Anon if some radiators have heat and others not, the problem isn't the boiler itself, it's more likely a closed radiator valve or a steam vent that's not working.

You probably need to replace the radiator's steam vent.

Diagnosis and repair advice for cold steam heat radiators is

at STEAM HEAT RADIATOR REPAIR

and at STEAM VENT TYPES, SELECTION

Most distant radiators not getting warm

Not getting heat at the furthest radiators but I have water at vent On 2014-01-30 by charles

Reply by (mod) -

Charles,

When you open an air bleeder at those cold radiators and get water out that's helpful, but it does not assure us that there is not an air blockage somewhere in the hot water piping for your system.

1. Check that the heating system pressure is sufficient to get water to highest floors
2. Feel along the pipes to identify where they begin to be cold; if that zone is running I suspect that there may be air in the piping that is not being bled out at the particular bleeder valves you are opening.

You may need to ask your heating tech to force air out of the system.

See AIR-BOUND HEATING SYSTEMS 

Boiler Conversion FAQs

Want Advice on converting from hot water heat to forced air heat

We are looking at repairing an old water boiler system or replacing it with a forced air.

Added to the problem is that all the water pipes have asbestos wraps so we have an abatement problem as well. This a very old converted system that leaks and the water tanks leak so the whole system needs to be replaced.

We also are looking at "mudding in" doing something else to deal with the asbestos. The radiators have not leaked yet but they are cast iron and old.

Our concern is if we will have a plugging problem with the switch to a circulating pump from a gravity system due to sludge and if leaks will show up when the pump runs and moves the old sludge. If it leaks somewhere after we have spent the money to cover the asbestose we have that loss of investement.

Of course we need the pipes removed and duct work put in if we go the other way. So far the the costs appear to be expensive and close.Is there any advice you can give to us? On 2012-11-25 by Lyle Bren -

Reply by (mod)

To give accurate advice really requires an on-site un-biased heating company or independent engineer, but in general, converting from forced hot water to forced air heat in a building can be close to prohibitive in cost if you have to add ductwork to replace that original hot water distribution piping.

I'd be looking at a new high efficiency hot water boiler.

About asbestos on your hot water heating pipes - asbestos on pipes is usually safe and legal to leave alone if it's un-damaged and won't be disturbed.

See our complete advice on that question

at ASBESTOS PIPE INSULATION 

Bottom line: Before even considering a heating system complete redesign and swapout of both the heating plant and distribution, I'd be sure to get ALL of the costs involved.

You can encapsulate asbestos on heating pipes and leave it in place regardless of going to a completely different heating system.

Heat converted from steam to hot water, technician questions pipes

I have an older house we have had for 12 years and have had several techs in over those years. It was converted from steam to hot water at some point before we bought.

The latest tech in (and he is the only one that ever said this) said the pipes were not converted and should have been. This is the background on the system.

That tech changed the thermocoupler, aquastat, and replace the power venting motor a month ago, and all was fine. Now the furnace is not working again.

Checked all the parts he installed, confirmed the pilot is lit and the thermostat is calling for heat. He recommends replacing the entire system, which we cannot afford.

He mentioned the circulator as a possible problem, but that it would be a crap-shoot and we are basically throwing darts in the dark at a system that should be replaced. he stayed at the house an hour after bleeding the system of air. At the time he was talking to me, his employee reported that the water was getting tepid, but not yet hot.

Assuming the system does NOT heat (he asked my tenant to call him in 2 days with an update), what is the chance it is the circulator (a $400 repair, he says), and if not, what other problems could it be? (Dec 1, 2015) Steve

Reply:

Steve

It is not necessary to "convert the pipes" when changing from steam to hydronic heat, but indeed some boiler and heat controls, vents and other features are of course changed.

The addition of mention of a circulator as maybe the problem makes me nervous.

You are describing a tech who has proposed two repairs: a $200-400 job and a $5000. or more job.

I'd ask the heating company service manager to send out an experienced service repair person.

Steve said:

Dan, thank you for your response. He actually is the owner of the company that went out.

And while he admitted that he was not that familiar with a system that had been converted from steam to water, he went on to tell me that the old steam pipes were too big to be pushing water to a second story, and that the furnace needed replacing... or it could be the circulator.

He drained the air out of the pipes... something I feel should have been part of replacing the aquastat, or really any service repair of a system that has not been operating for a few days, just as a precaution.

It started warming, so I thought the issue might be over and done with, but I just got a report from my tenant that she still does not have heat 5 days later.

Mod reply:

The size of the heating pipes may be bigger (for steam) than for forced hot water but that makes little difference except for the total volume of water in the heating sytem. I think there's a problem somewhere else.

Should an old boiler be replaced with electric baseboards?

I am from New Mexico and do not understand these boiler types of heating. My mom lives in St. Louis area, she is 92 and right no today I found out she has Pnuemonia.

She has not had the heating she has working for two years. She says her heat comes from water in the slab.

When she turned it on two years ago, it flooded three rooms.

They have a large attice room. I want to put vents and tubing in this area for heat. This would be possible wouldn't it? I can't let her live this way anymore. She won't come live with us. This will be the third. I cannot convince them that they cannot live without heat in Missouri.

I know she got the pnuemonia from the cold house.

She is using space heaters now which are dangerous. She only heats one room with them. She warms hers and her husbands pj's at night when they go to bed and then goes to bed in a cold room with electric blankets. She is a very stubborn woman and will not let us help.

Her system is probably from the 60's. We are going to have to force her to let us do something and I can't wait anymore. She says it is 40 in the house and it isn't even the worst of winter yet. She says her boiler is fine it just leaks.

Wouldn't it be better to try and put a new unit in the attic that is electric?

I forgot to tell you I have woodstoves that is why I don't understand Her system. We don't even have air conditioning here. Can you help me? (Dec 19, 2015) Beverly Hunter

Reply:

Beverly,

Replacing an oil or gas fired heating system with electric heat in St Louis is probably going to increase the home heating costs.

Start by having a trained heating service tech inspect the existing system to give as assessment of its condition and repair cost estimates.

You can then compare that with a new boiler cost.

Ask for specifics.

We don't replace a boiler just because "it's old" but we would consider the boiler's reliability and its operating cost when deciding when to replace it.

Bottom line: if the boiler repair costs are much greater than the cost to go to electric baseboard heat and if you can get the eletric baseboard heat installed more quickly, I'd consider that option in the case you describe - let's get your mom warm and safe ASAP. - Daniel Friedman

Can I replace my oil hot water furnace with my friend's steam furnace?

I currently have a an oil hot water furnace. A friend has a steam furnace she's getting rid of.

Can my hot water furnace be replaced with her steam furnace? On 2012-11-07 by Donna

Reply by (mod) - probably not reasonable

Donna,

Most likely the swap in you suggest is not economical, as radiators, controls, even distribution piping all are likely to need changes to convert from hot water heat to steam heat.

But depending on the steam boiler itself, its condition, type, and other factors it MIGHT be that you'd consider converting the steamboiler itself to hot water.

But I'im afraid that labor costs and new parts costs could at the end make you wish you'd just ordered a new hot water (hydronic) boiler instead.

Can I replace my steam boiler gas valve with a millivolt gas valve?

I have a gas steam boiler in my home.
My question is could i remove my gas valve and replace it with a millivolt gas valve.
I'd appreciate any information you could give me
Thank you - On 2012-11-27 by Frank Ammendolea

Reply by (mod) - probably not

Frank,
If you're trained or an electrical engineer, you could probably figure out how to swap in the "wrong" gas valve on a heater and make it work - but I'd not be willing to swap parts around;

The manufacturer of your boiler chose a control and matched its properties to all of the rest of the fuel and combustion and safety components - you're voiding warranty and perhaps making the system unsafe.

Maybe if you explain what's making you ask, we might have a different suggestion.

Gas Boiler Won't Run

Gas Boiler Burner Won't Ignite: bad thermocouple?

My gas fired boiler will not fire up. It was working fine for a month since starting it up for the season. Burner motor will start, pilot is lit and stays lit but burner does not ignite.

Thermocouple is 2 years old and so is the gas control valve and burner relay.

The burner transformer is putting out 24V but the is no 24V across the control valve terminals.

Would bad thermocouple allow the pilot to stay on while keeping 24V from the control valve? Thanks. On 2019-11-04 by Bob M

by (mod) - bad thermocouple is the place to start

Yes, a bad thermocouple or thermocouple that's not adequately connected at the gas valve and confirm it the pilot to continue to burn but think that there is no pilot because it's not properly sensing the flame.

That case it will prevent the gas valve from opening.

Replace the thermocouple and be sure that its contact at the gas valve is screwed snug into place.

See details at GAS PILOT WON'T STAY LIT 

If you are sure you have plenty of fuerl, and if the problem is NOT the gas pilot or thermocouple and if you have made dead sure that the end of the thermocouple tube is well tightened into the gas valve (remember the threads there may be opposite of usual, that is, tighter may be counterclockwise on a thermocouple end) THEN

the problem could be the gas valve itself.