Ground Source Heat Pumps
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Have not had that problem on radiator circuits here, but have had a couple in the electrical cassette with rusty water. One actually ate through the cassette body, so it had to be changed. The new HE seems to have a stainless steel unit, so we will see!!As Manuel says in Fawlty Towers: " I Know Nothing"0
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matelodave wrote: »I think it depends what sort of heating you've got. If steel or cast iron radiatorss, then it's probably a good idea. I'd guess that it's relatively easy to clog up a plate heat exchanger with crud
We've got underfloor heating all over so it's just copper piping to brass manifolds and from there all the heating piping is plastic so there shouldn't be any iron in the water.
Cool, thanks both. For the sake of £80 and a couple of hours work I'll do it.0 -
Despite having bought hundreds of clips from Amazon, none of them were quite the right size to keep the filter in place
Anyway, I ran the system without the filter for 10 minutes (as the filter has never captured any bits anyway) to see if the poor quality of it was causing the issue - but had the usual GT8/9 alarm after 5 mins.
The temperatures went:
45.9 / 34.6
54.3 / 42.7 (2 min later)
59.5 / 43.8 (5 min later, alarm triggered)
I later switched off the system, got my new multimeter out, and set it to 20k.
GT8: 3.87
GT9: 4.66
I switched the system on and read the temperatures a couple of mins later (takes ages to get in to this screen!) - it was 32.9 and 26.5, which would seem normal to me.
If we unplug these two temperature probes, could anything bad happen and would this stop the alarms?
@Patrol, I know you wanted to know if I had a manifold for my UFH... I've opened a panel in the floor I found, which is where the UFH heating starts. Not sure if this is what you were after:
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Hi Dee,
I've just been out and taken my filter out to check the circlip size (checked the filter while I was at it :-)).
I measured the unsprung diameter of the circlip at 22mm. It must have therefore been 21.5mm or 22.5mm to make it what is known as a 20 or 21mm od circlip (designed to go into a 20 or 21mm bore hole and then expand to 21 or 22mm once in). I'm sorry that I didn't measure to the 0.5mm, but I didn't realise they went like that :-)
These were measured on my pump which is an HT+ E9. YMMV.
Something like this http://simplybearings.co.uk/shop/p82674/Internal-Circlip-21mm-Diameter-Un-Sprung-Dia-22.5mm/product_info.html or this http://simplybearings.co.uk/shop/p82673/Internal-Circlip-20mm-Diameter-Un-Sprung-Dia-21.5mm/product_info.html or equivalent on ebay should do the job.
Edit: Or if you're worried about the filter not being right get this - https://jsenergi.co.uk/ivt-spare-parts/by-model/ivt-greenline-ht-e9/filter-ball-delsats-dn-20.html or https://jsenergi.co.uk/ivt-spare-parts/by-model/ivt-greenline-ht-e9/filter-ball-delsats-dn-25.html. Again, sorry but I don't know what the difference is between the DN20 and DN25. I would assume the DN20 is the internal one and the DN25 is the one on the collector loops, but don't hold me to that. Also obv. check they are compatible with your model.
Beardy0 -
Yes DN20 is the heating side and DN25 is the ground loop.
Would not agree on unplugging the 2 probes as 1) the pump may not even start and 2) they are there as a safety factor to prevent overheating.
Pity I did not have time when my pump was changed over, as would have taken the probes off and posted them to you.
Will try to see if our engineer has any suggestions, but will be after Easter when I can give you a answer.As Manuel says in Fawlty Towers: " I Know Nothing"0 -
Cheers guys, the probes seem to be fine from what I can see and the filter (whilst not perfect) isn't causing the problem either.
Next steps may be to cut out the beeping machine, or knock down the house and start again, or replace with a gas boiler
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You could try swapping two of the sensors over to see if the problem moves? Or a new temp sensor is https://jsenergi.co.uk/ivt-spare-parts/by-model/ivt-greenline-ht-plus-e9/001c-hetgasgivare-ntc-620mm-molex.html.
One of the things I've found really helpful is the logger I bought as you can leave it running, see all the temps, valve positions etc. on a graph and see exactly what is going on. http://husdata.se/default.asp?fullweb=yes. Money well spent in my case.0 -
Cheers, does one of the temperature readings above seem off normal to you?0
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The ohm readings do look about right, but I suppose they only need to be slightly out for it to be a problem. My thinking being it's free to swap two sensors over (say GT8 and GT9 swap for GT10 and GT11), and see if the readings are OK on GT8 and GT9, but dodgy and GT10 and GT11) so worth a go before trying anything expensive.
These are what they should be :-
degC kohms
0 15.280
5 11.900
10 9.330
15 7.370
20 5.870
25 4.700
30 3.790
35 3.070
40 2.510
so your readings of 3.87 and 4.66kohms do seem roughly right.
For interest, here is a graph of my GT8 and GT9 temps today (along with whether the compressor was on or and off and if the 3-way was sending to CH and DHW).
As you can see about 9degC delta when producing CH and about 8degC delta when producing DHW.
Edit: Do you only get a high GT8/GT9 delta only when producing CH, or also when producing DHW? If the delta is roughly right when producing DHW, then I guess we can rule out the possibility of one of the sensors being faulty.0 -
Unlike most of my plumbing, the wiring in the main GSHP box is really tidy, so it would be super difficult to move another couple of sensors over.beardymarrow wrote: »You could try swapping two of the sensors over to see if the problem moves?
I did open up the insulation and found the GT8 and 9 sensors:
and I loosened the cables and put them in some ice water:
GT8 reported a temperature of 1.8, and GT9 of 1.9 so they seem fine to me. When I wired them back up, I swapped the sensors over just in case it made a difference. Slightly less tidy wiring now!
The alarms (which normally trigger under both DHW and CH) went off after 5 minutes. The readings were after I turned it back on, and CH was being generated:
GT8: 38.0, GT9: 28.5 (start)
GT8: 40.9, GT9: 28.5 (1 min later)
GT8: 44.3, GT9: 28.5 (2 min later)
GT8: 46.5, GT9: 28.7 (4 min later)
GT8: 47.2, GT9: 29.1 (5 min later, alarm triggered)
20 mins later GT8 was 50.4, GT9 was 32.4
90 mins later GT8 was 49.5, GT9 was 31.80
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