How to keep a boiler system pressurized without tap water source

[mpilihp]

Hi setting up in floor heating system with a propane boiler for a shop that does not have a well or a water source to provide pressure.

Can this be done, do you just fill it and make sure there is NO air then seal it up? My plumber is basically saying thats all you need but im concerned since the boiler will be the highest point in the system that if water weeps out of the air relief valve that eventually it will have air in it and in the boiler.

Im also planning on filling it with glycol and my plumber is saying to fill it with water first to test for leaks. Seams like that would be harder to then ensure a proper 50/50 mix of glycol. Why not do a pressure test with AIR??

Thanks

Phil

 

[Tonty]

I pressure tested mine with air before I hooked up my wood boiler. You’d have to have a way to isolate the air bleeder if it’s on already. I’m not sure about your other question, it seems like it should work, but others on here will know for sure.

 

[salecker]

My boiler building does not have running water
Once you have a sealed system operating at temp and your pressure tanks are big enough for the expansion you should not be adding water.
I had to add an additional pressure tank to my original build because when i got everything up to max temp the system would overflow,then in the fall before starting it i would have to add water.Went through that for a couple years ,then added another pressure tank.Since then there has been no water discharge when i get to max temp.And every fall the system still has preasure and requires no top up.

 

[maple1]

How far away is your water source? Could just get everything filled and running. Then run a hose later if a need arises. I always keep my water feed shut off. Only open it if I need water. Like if I have to bleed a zone to get rid of an air pocket.

 

[slowzuki]

Very hard to find small leaks with air as its compressible/pressure holds steady a long time.

 

[salecker]

I pressure tested every part of my system with air,then pressure tested the complete system with air.
Found all the leaks and fixed them before liquid.Zero leaks once liquid was added.
I did fill my rads with water then pressurized them to 80 PSI for testing. I had found the rads laying in the bush .They had been there for so long that willows had grown through the sections and almost hid them.I had flushed the rads with acid to clean them,ended up with a couple that failed the leak test.
The guy who helped design what i wanted to build told me to test to 60-80 PSI.If everything passed at those pressures there should be no issues he said.
He had lot's of great advice, Test to at least 2x working pressure was the advice given,"God hates wimps was a favorite line from him.
14 leak free years of use so far.