Weil Mclain-Maintaining Boiler Pressure after glycol fill

Replaced the Crytotek 100 Poly Glycol in my home heating system. Completely drained the system. Pumped 30% mixture into my system with a transfer pump. Bled the air best I could. The system works and I have circulation but I am having to add small amounts of make up over the last couple of days. The system has an autofill plus backflow preventer but I have the autofill valved off because I do not want to dilute the glycol. Could the small amount of make up be needed to maintain pressure be a symptom of air working itself out through the air scoop? No leaks are obvious. Any thoughts would be appreciated.

Read more: http://www.doityourself.com/forum/ga...#ixzz3ItClFOVG

 

What type of expansion tank do you have, conventional or the bladder type? What does your boiler gauge indicate, pressure and temp, cold and hot?

Why did you add glycol to your home heating system?

 

I would have to say yes, your just purging out the last bits of air.
Keep track of how much you add.

Keep an eye out for leaks, but if you didn't have them before you should be alright now.

 

Expansion Tank is an Extrol 30. The pressures are 15 cold and about 19 hot. The glycol was already in the system when I bought the house. I am assuming this is because I have an air handler in the uninsulated attic. Regardless this is my first time changing/replacing the glycol.

 

Why did you see the need to replace the glycol?

 

Replaced the glycol because it had become diluted do the removal of an indirect water heater. I wanted to get the percentage back to 30% so I decided to replace it all. The old glycol still tested Ok from a PH perspective but it was pretty diluted.

 

I've heard of systems that have a large expansion tank on the water feed to the system... filled with glycol mix and pressurized to like 40 PSI. This feeds glycol mix when the system needs it and doesn't dilute the mix in the system.

Here's a commercially made product... no idea the price on this:

PRESSURE PAL MF200 Mini Feeder

http://www.axiomind.com/

Yeah... a little pricey...

http://www.supplyhouse.com/Axiom-MF2...eeder-6-Gallon

 

Maybe I missed it, but why do you have anti-freeze to begin with? Because of the air handler in the attic and that the house is routinely left unattended? My personal opinion is that hot-water heat is not suitable for such locations.