How much Glycol do I need for my Radiant floor heat ?

We had a leak in our radiant fool heating system (pressure relief valve) that we had fixed but we lost most of the original fluid that was in the system. It has an auto fill valve on it so it refilled with tape water as the fluid leaked out.

Now we find that we spots in the floor that freeze (by the doors or garage) when it gets 30- to 40- below.

Our house is 2700 sq feet and I am not sure how much glycol I will need to keep it from freezing to 50-?

What is the average cost of glycol?

Can I do it myself or do I need to hire someone to do it.

Can anyone help?

Thanks

Oh and I live in Alaska

Greetings Ron welcome to the Forum.

My experience with those solutions, is that it usually takes a 50%/50% mix, to get it down to a -50°.

Do you have a % Tester, where you can check the concentration ?

Ops Manual on your system, should give you the recommended concentration, and tell you how much volume it has, if you need to know that at some point.

Have a good Day !
S.W.

Ya, I think it is 50-50, the volume is what I am looking for. How much would I need. I have never seen a manual and we bought the house from the people that had it bult but they moved away.

Any way to guesstimate (sp)?

Ron,

My previous Post WAS the guesstimate !

Surely you could lookup some Mfg Material on the Internet about your system. Just general stuff will help you maintain it.

I'm not even sure about the 50/50. That's usually what it takes to get the freeze point down like you need.

You need to get a Tester !
It's a little Suction Bulb with a passive indicator on it, it sorta floats to the concentration point to give you a number. They're not all that expensive.

Take a sample of the solution from your system, and see just where it is, THEN go from there. Surely the installer left you some "Sample Points". A little Valve, where you can draw some out, and do test on it. You shouldn't need over a Cupful or so.
Don't you have anything like that?

Once you get the Sample, you can have other Bacterial and Chemical Test done on it, to see if it's in good condition.
Test like that will tell you if you're having any Scaling, which could be the cause of your perimiter freezing. There could be a flow issue, and then you'd need to run some De-Scaler in the system. (like cleaning the Radiator on your car).

Understand, I've never had to deal with a closed heating system like yours, where I needed to get it protected down to a -50!!!
I live in Houston Texas !
But, I have had experience with NORMAL stuff !

Look for a Maintenance Tag from the Installer on the system, anything that will lead you to some information on it. There should also be some sort of "Jug" where you can do a injection of the glycol, look for that too.

Have a Good Day !
S.W.