Gravity hot water heat.

mchema

I am new to hot water systems due to the fact I have lived with one

pipe heat for some time. Currently, my husband and I are looking at a

home built in 1910 that's a gravity hot water system. The problem is

the house has not had heat for 4 YEARS! Supposedly the system has been

drained "properly." I don't know what that means but the huge old

boiler must be removed per the gas company. Now my question is how

likely would leaking occur in the systems once it's back on line with a

new boiler? How brittle do pipes and cast iron get going through

extreme hot and cold seasonal changes?







I don't want to get rid of the beautiful direct and indirect rads.  But

I am worried that things were not properly winterized.  Mini duct might

have to be an option :( 

Gordy

Try before you buy

  I would have a home inspection done first.  If you really want the house I would write in the contract that the heating system must be operable once up, and running, or seller is liable for repairs at their expense. Or a new home warranty.  Is the new boiler going to be on you or the seller? Or is this an as is situation?



 If the system was PROPERLY drained before subject to freezing temps it should be okay.

 The only possible issue I see is the pipes being dry for 4 years will roughen up on the inside. This will change the dynamics of the flow once the system is operational again if it still ends up being a gravity one, but chances are they will put a circulator in with the new boiler install.



 I'm not a heating pro, but this is what I see to look out for. Maybe someone will chime in here with a possibly different opinion.



Gordy

mchema

About that

Yes this heating issue is all on the owner! They are offering a 20,000 heating credit plus reduction of the home purchase price.



 There would be no way I would purchase the home without a home inspection since the house has had no one in it for so long. Well that's not true but that is a different story.  I also worry about the plumbing. I didn't see any signs of winterizing. No pink stuff in the sink, no signs stay DON"T TURN ON. Like I have seen in many homes before.



OH the headache we put up with to own a dream.

Gordy

Don't Assume

 Yes the domestic plumbing crossed my mind. Obviously it must have been drained, and water turned off, or there would be a mess. But if they blew the lines out with air they should be clear. on the drain side they should have put the antifreeze in the p traps. Possible they have evaporated over the coarse of 4 years of no use.



 Look under find a contractor here, and see if there is someone in your area that would come out, and look the system over.  I would get bids to see how much to get the system up, and running before you purchase. Then at least you know where you are at for cost.  Make sure they do a heat load calculation with their bid so you do not end up with a boiler that is over sized for the home.



 I would also look into a modulating condensing boiler since you have to do a new boiler anyway. They modulate the burner to the load so they are very efficient in the 93% range. It may not condense which gets you a little more efficiency, but the modulation alone will save you money. You do not always need 180* water to the radiators all season. A regular boiler will be an on off type of setup with a fixed burner output.



 If the house has had insulation improvements since it was built chances are your radiators are over sized which is good, If they are over sized that means they can use lower water temps to heat the home which is beneficial to a mod/con type boiler the lower the water temps the more efficient they are.



Gordy

icesailor

Testing heat system and plumbing:

If you can find someone clever, they can take a portable air compressor and charge up the heat system and the domestic water system and find any leaks or breakages. I do this all the time. In the Spring when I start turning on water, I will charge up the whole house to be sure that everything is OK. I'd rather wipe up a air leak than a water leak. If there are any split pipes in a wall, you can hear the air leaking. With the heat system, you can charge the whole system and find any bad radiators or anything else. You do not need to have the water turned on. Just power for the air compressor. I have done this for real estate agents and inspectors when it was too cold to turn on the water. If I have a house that freezes up and has broken pipes, this is how I locate them.  

Brad White

I agree with Icesailor

Send in the Air Force. You will know very quickly what you have to do.



Our current house we just bought this past summer was built in 1913 and also has gravity HW as its core system (plus a few add-on baseboard zones, sigh...). But the gravity part is hard to beat, large Gurney radiators on outdoor reset and an ECM circulator. Ahhh.   So, I can totally relate to the period house you are looking at.



I wish you success, good outcomes of all tests and hope it becomes not a house but your home.