Conversion from steam to hot water in residential home

steamhotwater

I purchased a 1934 home 31 years ago which at the time had a steam boiler system. Over the next ten years I spent approximately $4,000 annually to maintain this system using plumbers who “knew” how to fix my system but never seemed to do so. As a result about 20 years ago I had the system converted to a hot water system. In the conversion the contractor did not change out the steam convectors to hot water radiators. Based on my lack of any technical knowledge, I believe my system is incredibly inefficient as steam convectors do not produce nearly enough heat with the water temperature of a hot water boiler.

So my question is should I replace the steam convectors with radiators and if so with cast iron radiators or panel radiators or just live with the inefficiency. Three additional points: 1) I live in the mid-Atlantic region so we have cold winters, but not New England or Upper Mid-West winters; 2) the existing steam convectors are located in recessed metal boxes in plaster walls with a metal covers, cast iron radiators would likely not fit in these shallow recessed spaces, whereas panel radiators would (obviously the metal covers would be discarded); and 3) how do I find a competent contractor in my area to evaluate my situation and to propose and implement effective solutions?

Thanks for your response.

Perplexed

Jamie Hall

First off, let's get one thing clear: there is a difference between efficiency and adequate heat.

I am not a bit surprised that you find that you have inadequate heat from the radiators. At best they will be able to produce no more than about 2/3 the heat they would have produced on steam. That is not a matter of efficiency -- only of the difference in temperatures.

At this point, since the steam system, regrettably, is long gone, your first step should be to insulate and tighten up the building as much as possible. Insulation, storm windows, that sort of thing. It's possible that in a building that age you may be able to gain enough that the existing radiators will do -- and save on fuel in the process.

Once that is done you will need to assess -- room by room -- how much heat you need in that particular space. It is, frankly, unlikely that any radiator -- panel or otherwise -- which is big enough to provide the needed heat will fit in the existing enclosures.

You or your contractor can then select the proper radiators for the system, and size the boiler properly to go with the radiators and the building --for that needs to be done to have any efficiency to speak of.

Which brings us to efficiency. No doubt the boiler you replaced 20 years ago was less efficient than a modern boiler would be. Also, no doubt that the boiler you replaced it with is not as efficient as a modern boiler might be -- if it is properly sized. There is very little difference between the overall efficiency (that is to say, gallons of fuel burned under specific outdoor conditions) between steam and hot water; indeed, there is none unless the hot water boiler is of the modern, fully modulating condensing variety and is properly sized (there we go again) and installed and piped correctly, with the proper controls.

It is a shame you replaced the steam system, but what is done is done.

As to finding a competent heating contractor for hot water heat, I would try first looking in the "find a contractor" tab on this web site. If that fails, but you can tell us where, exactly, in the mid-Atlantic region you are located, it is quite likely that we will know of someone we could recommend.

JUGHNE

Do you know the operating temp of the hot water system?
Did they change out the boiler 20 years ago or is it still the steamer boiler repiped for hot water.
Most likely in 1934 the steam system worked well and has extra radiation installed for the house. But has been knuckle headed by many, including the contractor who converted the system to hot water.

Where are you located?
Check above on the main site for "Find a contractor" near you.
Expect advice here to change it back to steam, a true comfort system.....heating is all about comfort.

You could leave existing radiation and add panels elsewhere to supplement what you have now.

JUGHNE

Could be simple things such as if they left the element/guts in the trap bodies that could slow down the water flow thru the convectors.

Any pictures of the boiler and it's piping...from floor to ceiling is good.

The Steam Whisperer

Or convert the system back to steam with a contractor that know his way around steam.

Steamhead

@steamhotwater , looks like that contractor took your money. Where are you located?

steamhotwater

Thank all of you for your comments, much appreciated. I am located in Chevy Chase, Maryland, a suburb of Washington, DC

Henry

We have done a number of conversions to hot water here in the Great White North. Cast iron steam radiators since 1917 were always oversized as they had to be able to heat each room with the window open. We have had no cases of lack of heat. We did have in some apartment the typical issue of a heavy curtain blocking airflow. The most important part of the conversion is removing the trap bellows and seat of the steam trap. You need someone to check each radiator trap. A modern mod-con boiler with outdoor reset will help bring your energy consumption down.

Steamhead

Really, @Henry ?

https://forum.heatinghelp.com/discussion/145002/actual-savings-over-steam-heating

@steamhotwater , we'd be willing to have a look, but your local guy is @Dan Foley . If he's backed up, get in touch with us.

steamhotwater

Steamhead,
Thanks for the info. Will try Dan and let you know if he is not available.
Best regards

jumper

Henry said:

We have done a number of conversions to hot water here in the Great White North. Cast iron steam radiators since 1917 were always oversized as they had to be able to heat each room with the window open. We have had no cases of lack of heat. We did have in some apartment the typical issue of a heavy curtain blocking airflow. The most important part of the conversion is removing the trap bellows and seat of the steam trap. You need someone to check each radiator trap. A modern mod-con boiler with outdoor reset will help bring your energy consumption down.

The way Ontario rent control worked; a good improvement/project (investment?) was to convert steam to hot water. Then some fourteen years later another good project (investment?) was to convert the converted HHW back to steam. Especially so for limited dividend buildings. Even original HHW may have been considered but that probably was too iffy.

Dan Foley

@ Steamhead

Thank you for the referral. We have worked on many steam systems in Chevy Chase with recessed convectors. Some have cast iron elements but most are Trane finned copper elements with internal orifice plates.

Hot water conversions don’t work well with this type of convector and it is not possible to drill out the orifice.

steamhotwater

Dan,

Yes I believe we have finned elements and no the conversion does not work very well. Are you interested in taking a look at what we have and see if something can be done to improve our system? Also the boiler itself has not been serviced for a couple of years and with the heating season on its way I would like to see what can be done.

Thanks,

Steamhotwater