Ground Source Heat Pumps

DeeWestern

Help! It turns out my GSHP has been leaking for a few days, I have a very wet and hot garage





Hot water is coming out of the hot water tank, via the pipe that's highlighted. It is a copper pipe that runs up, along, and then down between the hot water tank and the heating cyiinder to the ground as an emergency outlet.

I've opened up the main GSHP, turned off all the power switches and turned off the black handled valve that is under the blue arrow in the second photo. This seems to have stopped the water leak for now.

What could have caused this failure and how do I get it fixed?

beardymarrow

DeeWestern wrote: »

Help! It turns out my GSHP has been leaking for a few days, I have a very wet and hot garage





Hot water is coming out of the hot water tank, via the pipe that's highlighted. It is a copper pipe that runs up, along, and then down between the hot water tank and the heating cyiinder to the ground as an emergency outlet.

I've opened up the main GSHP, turned off all the power switches and turned off the black handled valve that is under the blue arrow in the second photo. This seems to have stopped the water leak for now.

What could have caused this failure and how do I get it fixed?

Hi Dee, that sounds like the pressure relief valve is opening. Does it leak water from the same pipe if you manually turn the knob on top of the valve (the prv is the one just to the left of the arrow in the second photo) half a turn (it shouldn't go any further if it's the prv)?

If it is that valve, you'd need to then find out if that was because the valve was faulty, or the tank genuinely is over pressure. I'd be surprised if it was genuinely over pressure, unless the gshp is overheating the water (what does gt3 get to at max?), so hopefully it's an easy job for you or any local plumber to replace the prv. If that sorts it, it was a faulty prv.

DeeWestern

Yeah, it's definitely that valve. I've turned it all off so hopefully it's not overpressure, but I can't check GT3. Glad to hear it sounds an easy fix.

Is it a certain type / size of PRV that I can get the plumber to bring with him?

beardymarrow

DeeWestern wrote: »

Yeah, it's definitely that valve. I've turned it all off so hopefully it's not overpressure, but I can't check GT3. Glad to hear it sounds an easy fix.

Is it a certain type / size of PRV that I can get the plumber to bring with him?

Ideally they'll need to know the size and type of the 2 connectors into it, but most importantly the bar rating from the top. Might be best to email him/her a side and top view pic of it to be safe. They might well just bring the right rating one and then just adjust the pipework to fit.

lovesgshp

Missed some of this activity, as have builders in and half the back wall of the house is out due to them repairing the earthquake damage. Beardy is giving very good advice as always, so is worth following his comments.
frslam: also make sure you have bled any air out of the DHW tank, just to make sure that it is heating correctly.
DW: Are you still getting the gt8/9 alarms, or did you change the connections as advised? Pressure relief valves can be a problem especially after a few years of use. There will be the relief pressure noted on the valve, so you also need to check the supplied pressure to it as well. Normal pressures are about 4bar before the valve opens.

DeeWestern

The plumber came round this morning, swapped out the PRV and also the two flexible hoses. Cost £140.

Leak stopped as expected, but my GT8/9 alarms continue unabated - and no debris in the filter either. Totally exhausted on ideas as to what this can be - other than the ongoing beeping, it works fine though.

beardymarrow

DeeWestern wrote: »

The plumber came round this morning, swapped out the PRV and also the two flexible hoses. Cost £140.

Leak stopped as expected, but my GT8/9 alarms continue unabated - and no debris in the filter either. Totally exhausted on ideas as to what this can be - other than the ongoing beeping, it works fine though.

Cool, that's good, at least you're back up and running.

The flexible hoses, are you talking about the ones within the GSHP that loveshgsp recommended were replaced? Did he check the pipework for blockages?

DeeWestern

Yes, the flexible pipes GSHP recommended for the beeping. No checking for other blockages, didn't think this had been asked for.

lovesgshp

DW. Sorry to hear that changing the pipes did not solve the problem. I am checking if there is a possibility that the black immersion heater unit could be partially blocked as the flow does go through that. Are there any rust stains around the very bottom of that unit? ( there is a square base, which has a seal and I have had one case where the seal had slightly perforated and caused a rust build up inside the unit, but it did also show outside as well).

frslam

Many thanks for the replies, very helpful and knowledgeable. Yes lovesgshp, I've already bled air out of the tank, always the first thing I do. Last time I had work done on my system, replacing a circulating pump inside the GSHP (floor heating - was actually a leak in the joint above it) I asked the plumber to check the strainer for the ground loop (inside house - flow). I told him there should be a retaining circlip holding the filter in place. He took the screw cap off and there was nothing there, no circlip and no filter. I was watching at the time so I know he's telling the truth. The only other time that was opened was when an engineer came to service the Heat Pump under warranty, it needed a new 3-Port valve. I know while the engineer was here he told me he was going to clean the filters. I wonder if he dropped something behind the GSHP which would be inaccessible. On another note, does the E7 + HT consume the same amount of energy when it's space heating as when it is water heating, and what is the actual consumption when it is running? Any links to where I can buy the filter and circlip would be appreciated, hopefully there'll be no long term damage of the GSHP because of the missing parts.