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Removing Steam Heat System?

We live in a 1920 Sears and Roebuck kit house with a one-pipe steam heat system. We have a Weil-McLain boiler that was installed at least 20 years ago. According to its specifications its input is rated 240.000 BTU/hr and output of 192.000 BTU/hr. The system is noisy and our gas bill is very high every winter (up to $400), but it has not failed us yet. On a side note, in the 1980s a separate A/C system was installed - one unit in the cellar and a second one in the addict.

My two questions are: (1) When should I replace my heating system and (2) what should I replace it with?

Re: Removing Steam Heat System?

From the numbers you give on the unit, that's quite a large boiler.

Is this a large house--could you provide more info as to the total square footage of the building, the amount of insulation in exterior walls & attic, the condition of the windows (tight or drafty)???

The procedure recommended is to first do at least a basic free heat loss calculation here on the internet (below) to decide how efficiently (or inefficiently) the heating system is heating the building.

In the end, you'll have to get several heating contractors in your area to come over & look at the system to advise what is best, something that can't really be done via the internet.

It is also important to install as much insulation into the exterior walls & attic as they will take (R19 for the walls & R40 for the attic)---not matter what else is done, this alone will go a long way to cutting heat bills; and drafty windows should also be replaced with new ones.

I've always favored forced hot water heat---I don't think you'd be comfortable with forced hot air (the other major option) if you've enjoyed radiator heat (which combines the good qualities of convective and radiant heat).

If it DOES come down to changing to forced hot water (perhaps baseboard) or something else, you are probably faced with changing everything---the boiler & the distribution system (the radiators & associated piping), since it is usually not possible to convert a one-pipe steam system to a forced hot water system (keeping the radiators).

This would add considerably to the cost of the conversion, especially if it is a multiple story house, where new piping/tubing would have to be snaked thru walls to the new baseboard.

On the other hand, the new system would no doubt be much more fuel efficient and save money on gas.

Since you have an AC system already in place (I assume with extensive ducting), another option might be to integrate a force hot air system into the AC ducting; again, local heating contractors would have to come over & answer if it could be done & offer a free cost estimate.

If funds are tight, or you intend to move in the near future, one option would be to just put in a new steam boiler---sometimes a new steam boiler combined with getting all the steam piping & rads balanced & up to snuff can improve fuel efficiency.

Please post back with the requested info.

Have you consulted any local heating contractors about this yet??


Re: Removing Steam Heat System?

Your comment about the size of our boiler is very interesting. The house as only two floors and a rather small addition downstairs - about 2000-2500 sft altogether. Since we moved in, we have insulated the attic. Having a balloon frame (so we were told), we were not able to improve the insulation of the walls. The windows are probably still original, but they are supported by storm windows.

My wife prefers radiant heat as well. However, I am concerned about the cost and mess that the installation of new distribution system for hot water might cause.

We hired plumbers to maintain our boiler, but I wasn't sure about their expertise with steam heat. Is there an easy way to check their credentials before they are my basement?

Re: Removing Steam Heat System?


There are still a precious few techs who are experts on steam systems---perhaps you could consult the Yellow Pages under "Heating Equipment" & talk to some of the people at the heating supply houses in your area to get a referral.

I would say your boiler is twice as large as it should be--the other factor would be how efficient (or inefficient) is the boiler??

Most new boilers are 85% to 95% AFUE efficient (meaning 5% to !5% of the heat is going up the chimney & the the rest is used to heat the house.

With a steam system that old, it could be no more than 50% efficient---50% of the heat is probably going up the chimney.

That's why it's usually so important to get a new boiler---even a $1600 run of the mill boiler can get 83% AFUE & thus save a lot of gas.

I also have balloon framing--these houses usually lack firestops (crossmember 2 X 4's between the studs)---not only will a fire (God forbid) race up the walls, but they also should be installed so insulation can be blown into the exterior walls.

A very basic heat loss calculation is to take a heat loss factor between 25 & 60 & multiply by the square footage---usually, a half-way decently insulated house in a cold climate with an efficient boiler requires between 25 btu/hr to 35 btu/hr per sq.ft. of house space to heat the building.

Thus, 2500 sq.ft. X 40 = 100,000 btu/hr--is the amount of heat oozing out of the walls on a cold day if you have a house that needs some wall insulation & you live in a cold climate.

A tighter house would be: 2500 X 30 = 75,000 btu/hr or even tighter: 2500 X 25 = 63,000 btu/hr---you can see what a difference this is---you can easily get an insulatied house that needs a boiler of 65k or 75k btu/hr to heat it---not the wasteful boiler you have now---192,000 btu/hr divided by 2500 sq.ft.= 77 btu/hr per sq.ft. that is needed to heat your house now---that's WAY too high---it should be 35-40 btu/sq.ft, not 77.

It's typical to see a 30% to 40% drop in fuel usage as soon as a new system is installed---that's a lot of savings.

The least labor-intensive conversion would be forced hot water baseboard---they can snake the flexible PEX tubing thru the walls & wall cavities to fit the baseboards in each room.

If you click onto my name & read some of my past posts on heating systems, you will get links & types of recommended boilers.

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