Ground Source Heat Pumps

Strummer22

Re: previous post the temp sensor has been fixed and my GSHP no longer thinks it's Dante's inferno outside.

Several months ago we had a central heating leak in an unknown location and our plumber dosed the system with leak sealant chemical (this or something similar: https://www.screwfix.com/p/fernox-f4-central-heating-leak-sealer-500ml/766pp). I've now been informed that this was a bad idea as it can compromise the efficiency of heat exchangers (although it did fix the leak). 

Our GSHP has a buffer tank - an Elbi Puffer Plus 200 accumulator. I am trying to figure out whether the water from the central heating just stays in the buffer tank and is heated by a coil inside it, or whether the water from the central heating actually goes into the heat pump heat exchanger? I think it's just a tank, no coils, so potentially the leak sealant fluid could affect the heat exchanger.

I am still getting decent DT on the hot water side (4.7°C right now), and a DT of 2.6°C on the brine side. Do those numbers look ok? What should I look out for if the leak sealant is making the system unhappy?

MultiFuelBurner

I mean a leak sealant product is that like one you put in your car cooling when you have a leak and is known as the temporary fix whilst you put the car up for sale before it fails?

I don't like the sound of that at all to be honest but await others response.

Strummer22

Yes hoping for more responses. Our plumber used the sealant as we had no idea where the leak was (no evidence of it anywhere, besides the pressure dropping). The sealant says it won't block heat exchangers... 

Heat pump got an alarm this morning! Low evaporator flow and low brine outlet temp. The evaporator and brine are on the ground loop side but presumably could be affected if the performance of the central heating side of the heat exchanger is compromised? I hope this doesn't get expensive