Ground Source Heat Pumps

beardymarrow

DeeWestern said:

ARtYXiFy said:

DeeWestern,
Your analysis is quite right, there is a problem with the flexible hoses that go to and from the heat exchange unit. Although they are flexible and have a rubber insert they also have a stainless steel covering both internally and externally and are therefore ferromagnetic. These hoses act as a beautiful magnetite trap and over the years will have gradually occluded and now the flow through them will be really quite reduced.This is the engineering equivalent of human angina. Put a magnet on them to prove it to yourself.
This firm can supply replacement hoses.           jsenergi.co.uk 
Type in these search terms:

Slang¾ LöpMutt90 ° ¾ LöpMutt¾

and

Slang¾ utv¾ löpmutt¾

Personally I had a plumber do the job, though you may be very capable. It will recur but many years away hopefully. You could try putting a magnetic filter in, flush the system and refill with inhibitor. G8/G9 (the Delta) should now drop back into the acceptable range of 7-10 degrees.

I've ordered these two pipes, and hopefully they will finally - after many years - fix the incessant alarms!

How do I swap them over? Is it a case of killing the power, pulling the handle that stops the flow (where you can get access to the thimble particle filter), then unscrewing the pipes with a spanner? Or is loads of water going to spill out as soon as I unscrew it?

Should I put PTFE tape on the joints? Anything I need to do after putting everything back together - refilling or bleeding anything?

Thanks!

Yeah, kill the power, turn all the valves off including the one at the bottom of the pump where it connects to the bottom pipe and undo that pipe from the pump. Water will come out, but stick it in a bucket quick. It'll take a while to drain. The alternative is to drain the whole system, which is a pain.

I had to use ptfe tape on the top hose where it went into the bottom of the immersion heater. That fitting was a bit of a !!!!!! on mine as the fitting is really narrow and my spanner was too wide. 

You'll need an olive puller to get the olive off the end of the bottom pipe and a new nut.

I'll be honest if you're not confident, get a plumber to do it. It'll take them half an hour. 

markin

This thread is now in the wrong forum, it's electric.

beardymarrow

markin said:

This thread is now in the wrong forum, it's electric.

Sort of :-) Most of the energy is coming from the ground, the electricity is just used to pump that energy into the house 

DeeWestern

beardymarrow said:

I'll be honest if you're not confident, get a plumber to do it. It'll take them half an hour. 

Perfect, just the concise advice I needed. Of course, being a GSHP it is hard to persuade anyone to touch it here - I contacted 14 plumbers just after you posted, they were either busy for the foreseeable future or don't work on heat pumps.

In the meantime, things have gotten much worse. You may recall my GSHP has alarmed for years and years about the high GT8/9 delta (but I had plenty of heating and hot water) and we've tested everything other than the 2 flexible hoses (for which I now have replacements on hand).

Now I'm getting no heating, and hot water seems limited (it was once tepid for the first time I can recall). Does anyone have any advice as to what might need fixing?



The red tank was showing a 0 pressure, I've repressurised it but still no joy. The alarms are HTF Out Max, High Pressure Switch, Electrical Cassette.

The black electrical cassette (black cylinder under the top 3 way switch) is very hot, and the GSHP alarms very quickly after a fault is acknowledged.

The three way switch is making noises when operated, but the red disk doesn't seem to move. Both outputs from the 3 way switch are hot.

Touching the pipes on top of the GSHP main unit,  Heating supply is v hot, heating return is cold. DHW supply is v hot, DHW return is tepid. 

GT1 On 39.1 / Now 16.1 
GT2 5.1
GT3 Tgt 47.9 Now 41.3
GT6 54.6 (was 22.4 the other time I read the figures this week)
GT8 60.0 (was 18.0 the other time I read the figures this week)
GT9 24.6 (was 15.4 the other time I read the figures this week)
GT10 7.5
GT11 6.3

Heating in the house is being demanded.

Is it the 3-way switch that's knackered and causing the lack of heating? 

Anyone have advice as to anyone who can either sort everything or replace the flexible hoses in Durham?

Thanks all!

beardymarrow

Wow, yeah that GT8 to GT9 delta is crazy high. That's usually because of too low a flow over the pump, and that would also cause the HP Switch to alarm and HTF out Max to be hit. My guess from your info is that the 3-way is stuck halfway and that's causing a blockage, and also why both outputs are hot. The cassette has probably over temped too, so that will need resetting from the button on the bottom of it (and maybe the breaker), but no point until the problem is resolved, and it'll run without the cassette anyway.

If you operate the 3-way valve from the menu (press and hold menu for 10 seconds to get into installer mode and then use option 5.3) does the red disk move. Can you send a photo of it, showing what position the red disk is stuck in?

Can you pull the clip sideways out of the base of the 3-way actuator and pull the grey box off so you can manually move the valve with an adjustable spanner? Does the actuator move if not connected to the valve itself? You'll know then whether the valve is buggered or the grey actuator motor. When you refit the actuator box make sure that the rectangle hole on the bottom of it is in the same position as the bit on the valve that goes into it.

I had the same response from my plumber. He was here fitting a magnetic filter and I asked him to put some PTFE tape on the top flexible hose where it leaked while he had the system drained but his boss said he wasn't allowed as if he broke something they would have to pay someone else to fix it as they had no experience. So I did it myself :-)

I've only ever used ICE Energy (ages ago, obviously), but I did call Alto when I got stuck once to ask for an engineer to come out and they just told me what to do over the phone for free, so I'd definitely use them in future if I needed someone.

DeeWestern

beardymarrow said:

Wow, yeah that GT8 to GT9 delta is crazy high. That's usually because of too low a flow over the pump, and that would also cause the HP Switch to alarm and HTF out Max to be hit. My guess from your info is that the 3-way is stuck halfway and that's causing a blockage, and also why both outputs are hot. The cassette has probably over temped too, so that will need resetting from the button on the bottom of it (and maybe the breaker), but no point until the problem is resolved, and it'll run without the cassette anyway.

Thanks so much. Will have a play over the weekend - when the valve is moved manually, is there a position I should put it in to flow water to the heating? (is it obvious once I've taken the cover off?) I think I rely on the electric cassette, any tips on finding the reset button? Seems to be on the side at the box underneath the black cylinder according to the manual...

Operating the 3-way manually does make a sound like the actuator is working, which I guess is bad news for a manual over-ride to get some heat.  The red disk doesn't spin at all though.

beardymarrow

From that photo it is in B, which is heating mode. Difficult to tell, but doesn't look perfectly lined up (might just be the angle). One of the 3 legs of the disc should point directly at B or A.

The valve has got a black plastic bit that fits into the underneath of the actuator, one end of which is rounded. There's a few positions it can go in, but horizontal with the rounded end left is heating and round ended right is hot water.

You need to figure out if it's the grey actuator or the valve itself that's sticky. If it's just the grey box, that's an easy self swap with no plumbing as it just plugs in and out. If it's the valve itself, you might find there's a bit of crud caught in the internals of the valve and turning it manually a few times frees it up (but it is likely to go again).

The red disk (and the valve itself) should turn 60 degrees on each activation as you can see below.

Here are the 4 positions of the valve that mine goes through.

Heating Mode (i.e.


Hot Water Mode (i.e. A)


Heating Mode (i.e.


Hot Water Mode (i.e. A)

DeeWestern

Thanks so much again.

Was easy enough to get the actuator off and on... but no helpful conclusions.



The valve turns freely, I moved it 360 degrees a few times in both directions.

The actuator itself turns fine when triggered manually.


The GSHP is trying to get DHW water (as it's pretty cold right now), and when operating the output was pointing to B. It seems as though when you turn off the GSHP it returns the valve to A. 

The DHW output pipe was hot, as was the heating pipe - but I think this is just heat transferring along the valve rather than water flowing though both. 

After I kept everything off for 30 minutes to cool down, I moved the valve to B and ran the GSHP. The DHW pipe heated up v quickly, the heating pipe remained cold.

Values at this point were:
GT1  36.0 / 17.5
GT2 8.7
GT3 47.9 / 26.6
GT6 62.6
GT8 66.9
GT9 17.7
GT10 6.6
GT11 4.6

GT9 remained pretty constant, GT8 rocketed up very quickly (1 min) to 70.0 degree and cut out with a high GT8 error. 

I let it cool down a bit, moved the valve to A and ran the GSHP (which thought it was delivering DHW again). The heating pipe heated up v quickly, the DHW pipe didn't get warmer. This time though the GT8 value fell for a few minutes, then rose up to 70 - took about 4 minutes this time.

So it seems like the 3 way valve is fine, as is the actuator, but there's a significant flow restriction elsewhere. Also suggests there's no issue with the radiator flow / heating pumps as we maybe thought before.

Could the blockage be anywhere other than the particle filter and the 2 flexible pipes? 

beardymarrow

DeeWestern said:

Thanks so much again.

Was easy enough to get the actuator off and on... but no helpful conclusions.

The valve turns freely, I moved it 360 degrees a few times in both directions.
OK, good.

The actuator itself turns fine when triggered manually.
So, does the red disk move now when not connected to the valve, what about when it is connected to the valve? Or maybe the red disk doesn't move, but it is moving the valve anyway?

The GSHP is trying to get DHW water (as it's pretty cold right now), and when operating the output was pointing to B. It seems as though when you turn off the GSHP it returns the valve to A.
DHW would be A (water flows through the right hand pipe). Heating is B (water flows through the left hand pipe). When the GSHP is turned off it should point at B, not A.

The DHW output pipe was hot, as was the heating pipe - but I think this is just heat transferring along the valve rather than water flowing though both.
Yes, I agree. You'd tell better if the pipe is still warm further along or gradually cools as you move away from the GSHP.

After I kept everything off for 30 minutes to cool down, I moved the valve to B and ran the GSHP. The DHW pipe heated up v quickly, the heating pipe remained cold.
B is for the heating. I guess you mean you moved it to A?

Values at this point were:
GT1  36.0 / 17.5
GT2 8.7
GT3 47.9 / 26.6
GT6 62.6
GT8 66.9
GT9 17.7
GT10 6.6
GT11 4.6

GT9 remained pretty constant, GT8 rocketed up very quickly (1 min) to 70.0 degree and cut out with a high GT8 error. 

I let it cool down a bit, moved the valve to A and ran the GSHP (which thought it was delivering DHW again). The heating pipe heated up v quickly, the DHW pipe didn't get warmer. This time though the GT8 value fell for a few minutes, then rose up to 70 - took about 4 minutes this time.

So it seems like the 3 way valve is fine, as is the actuator, but there's a significant flow restriction elsewhere. Also suggests there's no issue with the radiator flow / heating pumps as we maybe thought before.
Agreed

Could the blockage be anywhere other than the particle filter and the 2 flexible pipes?
The only other thing could be the internal pump is blocked or on it's way out? It's at the bottom of the long vertical pipe and the bottom of it connects via flex pipe to the heat exchanger. Can you take the metal disk out of the front (don't worry only a little bit of water will come out) and turn it manually with a screwdriver?

Without knowing the state of those flexible pipes and swapping them I wouldn't waste too much time on anything else. Get that sorted first. Maybe have a look and see what you need to do. It's more daunting than it really is. Or a friend who is handy could help? Doesn't need to be a plumber, just someone who has an olive puller and can use an adjustable spanner and PTFE tape :-)

Comments above in bold

lstevensuk

Just playing around with my IVT heat pump trying to learn a bit more about the different settings (any good resources on this?). I came across setting 8.1 - Additional Heat - Setting additional heat timer. This is set to 120mins - what does it actually do and can I turn it down?