PEX Heat Pump panel questions

[Crazy Legs]

I filled my PEX floor heat in my garage for the 1st time this weekend and i've come up with some questions,

I put 20 gallons of RV antifreeze and 20 gallons of garden hose water aka 50/50 mix and turned the pump on after several hours of bleeding air out of the system i have 1 leak that i can't get stopped, its the purge valve fitting that has a rubber washer that seals it. it don't seal worth a damn, i put teflon tape, silicone, fitting paste and it still won't completely seal when the pressure builds up from the hot water heater. I installed a shut off valve so i can shut off the pressure so its not pushing on the purge valve but i'm not sure if thats correct to do that. What do you think.

My only other issue is, i turned my 40 gallon electric water heater on and it works good but how do i test to see if both heating coils on working rather than just one? Only reason i'm concerned is because as soon as the water heater gets hot i can turn my pump on and within 10 min the hot side of my water heater is barely warm. is my concrete just soaking up the heat that much and will eventually get caught up or am i doing something wrong with the Thermostatic mixing switch on the panel??? my input heat from W.H. is 120 degrees.

 

[kbs2244]

What kind of pressure are you talking about?
You should have an expansion tank of some kind in the system.
And yes, it is going to take some time for the slab to get up to temp on the first turn on.

 

[Crazy Legs]

thats a good question, i'm not sure about the pressure. i've got a 2 gallon expansion tank inline on the hotside between the hot water heater and RHP-1 pump.

 

[kbs2244]

That expansion tank might be too small for a system that big.
That is a common size for home hot water pipeing. But they don't have 40 gal in them.
Can you get a small well tank? 20 gal? You should never use it all, but it will give you a big cushion.
For a low cost experment, make it an open to the air system, with the expansion tank vented to the air. You will be able to see how much expansion you get.