copper pipe feedback

mattmia2

a year or 2 ago a homeowner and a contractor were posting about connecting a steam boiler to 2 different gravity hot water system that they thought were steam at almost the same time. contractors that don't know steam see huge pipes and think it must be steam and try to put a steam boiler on gravity hot water.

i think i was thinking of suggesting this earlier. there are 2 pipe air vent steam systems but yours doesn't look right for that.

it is possible to put hot water trim on the boiler and make it a hot water boiler although the manufacturer usually doesn't sanction that and that boiler is probably massively oversized for a hot water application in your house.

pecmsg

Pictures of the piping and radiators?

nycbones

I am attaching the proposed re-piping diagram for conversion to hot water. Guessing folks will find that of interest. Also a few photos of the convector radiators. I was told that all the steam vents on the convectors will need to be swapped out for the proper ones for the hot water system. As usual, thanks!

hot water repipe.jpg

convector close.jpg

convector A.jpg

convector 2.jpg

Ironman

Well… those are convectors, not radiators. And, there are two pipes connected to them, but someone’s attached an air vent. Are there any traps that you can find on the system?

It never ceases to amaze me how some folks in this trade can knucklehead things so badly.

nycbones

I couldn't find any traps. The steam expert I hired (who is legit and had been recommended in other discussions on this site) looked at the convectors, checked the piping in the basement (which is almost entirely copper), and drew the schematic for the conversion. He seemed to think that the convectors would work fine with the new system as long at the air vents were swapped out for "coin valves" (at least I think that is what he said needs to be installed in place of the current air vents on the convectors). I am willing to give this latest fix a shot with the hot water, but this whole ordeal has been beyond frustrating. If this doesn't work I think I am going to tear out everything and move to forced air… not sure if there is another alternative since the boiler system seems to have been so mangled over the years. Urgh.

mattmia2

i mostly like that proposal, it is more or less calling out the right things, but did they do a heat loss calculation? if you reuse the old boiler you can't do much to change the boiler size but it will tell you what sort of a mismatch you are dealing with.

I would also like to see the right valves and drains to purge the 2 branches separately at the boiler. You may or may not be able to get enough of the air out by purging alone but it will make bleeding less work even if it doesn't get enough air out to start flow in every convector.

I'd throw in a dirtmag/discal for the air separator because it will also get you magnetic dirt separation. It is less important on a mostly copper system but it is still old and has had time to collect dirt.

I don't see the circulator but the expansion tank and air separator should be before it and before it branches off to the 2 circuits. The way it is now the circulator is pumping in to the expansion tank which is wrong although usually doesn't cause a problem. Until it does.(actually they did it right, the drawing was a little confusing)

I would put manual bleeder valves on the convectors because it looks like your convector cabinets just lift off and automatic bleeders inevitably leak after a while and that would go unnoticed inside the convector cabinet.

Ironman

It looks like the guy you’ve got is on the right track. I’d go with his recommendations.

You may see if the one who installed the boiler will cover some of the costs of the conversion back to hot water.

I needn’t remind you that it’s not good to make a decision when you’re angry or frustrated. Going with forced air in an old house is not a good decision.

nycbones

The silver lining at this point is that the guy who did the boiler install is willing to cover the cost of the entire conversion back to hot water. I think he feels bad and wants to do the right thing. Plus the cost isn't much different than the steam re-piping he had agreed to do. Hopefully that holds true. He is going to try and do it in the next week.

Also I am happy to see that folks are in general agreement with the new schematic and hot water recommendations.

KC_Jones

I'd speculate that boiler is roughly double the size it needs to be for the house. Glad you are getting it figured out at least.