Ground Source Heat Pumps

lovesgshp, thanks so much, fingers crossed for tomorrow then! :-)

Welcome to the forum.


You will need to give manufacturer and model for our resident expert - lovesgshp to assist.

So my system is dead... 
4 days ago, the GSHP had no power (box 1, old photo!):

Taking the cover off showed one of the fuses had tripped:


Flicking the green one back up got me back in business. Unfortunately, 3 days later it died again. And this time none of them had tripped:


My house's fuseboard was fine too. I turned off all the power and turned it back on just in case that helped. And removed and re-inserted the cat5-style cable going in to the main display unit.

I'm now stuck. Is there a fuse in the display unit that may have blown? I am not able to take resistance readings or use a voltmeter. Any thoughts on what a root cause could be? 
4 months ago I put some paper on top of the speaker to make it quieter (it's been beeping for 5 years+ with a high GT8/9 delta that we've never been able to solve), could this have caused the issue?
Is this a job for a GSHP specialist, rather than a plumber?

lovesgshp said:

I think your first course of action is a electrician. If you have the full manual for the pump, then he can check electrical resistance on the circuits. It is at the end of the manual.

With GT8/9 alarms, for 5 years, then they are usual simple problems, e.g blocked filters, pump speed, 3 way valve sticking. Temp/alarm data is always the best way to sort these things, so if you get back to a working circuit then you can give more information.

Had one here in Italy where a mouse decided a cable was a nice snack!!!

Thanks, will try and find one to come check this out. I've got the HT Plus PDF with installer guide - what resistances should I point the electrician to? There's a table for sensors and a very limited wiring diagram, but this is more a lack of power.

Glad you could respond - was getting a touch worried after 24 hours, hope you, your team and your family are doing ok.

We have tried most things for the 8/8 alarm - it's goes off even when on hot water, the 3 way seems fine, it alarms when the filter is taken out and the pump is at full speed. You suggested the flexible hoses should be replaced, and we weren't convinced the plumber actually did this (I wasn't there when he attended unfortunately), so was going to get Alto to do this and service the system if I needed a new display screen.

A broken valve was replaced by a plumber 3 years ago, but the system hasn't been serviced or had any work done to it in 8 years or so. Do you think it's worth proactively replacing anything (like the 3 way valve) or getting a 'service' if I have to have an GSHP engineer attend anyway? Other than the regular alarms (!) it works perfectly.

Last October saw some High Pressure Switch (HP) and HTF out max (GT8) alarms,  but the system kept on trucking.