Ground Source Heat Pumps

lstevensuk

beardymarrow said:

lstevensuk said:

beardymarrow said:

Patrol said:

lstevensuk said:

Thanks again @beardymarrow . Alas it has tripped again   Am I assuming that's a call out?

Anyone know of an engineer in Bedfordshire area? I normally use Alto Energy.

Can't help with details but it sounds like your soft start has failed. If you're still getting hot water the unit has probably been set up to use the cassette so running at 6kW rather than the lower ground loop consumption and that would explain the smart meter alerts. Much better to happen now than in the depths of winter

I haven't ever needed to use Alto, but it's who I would use. I phoned them up once to ask them to come to a problem I had, and they actually told me how to solve it myself over the phone, which I was super impressed with. I'd never been a customer of theirs either.

You could try just replacing the capacitors in the soft start. They are just cable tied into the soft start box and the most likely failure mode. Be very careful as even with the power disconnected they will pack an almighty punch if you touch the connectors and they aren't faulty.

Alternatively a whole new soft start unit is about £650.
https://www.ivtspares.co.uk/collections/ivt-greenline-ht-e9-1x230v/products/ivtsp10209
(although you'd need exactly the right one for your unit, this is just an example for an HT+ E9 which is what I have).

Compressor would be about £1500 https://www.ivtspares.co.uk/collections/ivt-greenline-ht-e9-1x230v/products/ivtsp10055 and that's definitely not a DIY job due to the refrigerant (so hopefully it's not that) :-)

JS Energi also do spares - https://jsenergi.co.uk/ivt-spare-parts/by-model/ivt-greenline-ht-plus-e9.html

Thank you again! Definitely going to try replacing the capcitors first. Wasn't expecting a bill that big

Hi,
I was curious so I have just been out to check the resistance of my capacitors and the compressor, so I know in future if I have the same problem is it the capacitors or is it the compressor. This is on my IVT HT+ E9, so your values may differ slightly.

With everything wired up, but the GSHP switched off
Compressor Run Winding 1.5ohms - Terminal 2/N (Common Blue Wire) to 4/T1 (Run Black Wire) on the Danfoss Soft Starter
Compressor Start Winding 2.3ohms - Terminal 2/N (Common Blue Wire) to Brown Wire connected to Run Capacitor (Smaller silver one) (or Terminal 2 on Start Relay)

Capacitors - Check for short circuit. You should get a reading across the terminals which will then rise to open circuit (OL). This is easiest to check by checking between 1/N and 3/L1 on the Soft Starter.

Ah thanks for that will pass it on to my electrician. Funnily enough he was over at the weekend writing details down for the capcitors. We sat there for 2 hours waiting for it to trip - nothing!

Going to replace them just in case though

beardymarrow

lstevensuk said:

beardymarrow said:

Hi,
I was curious so I have just been out to check the resistance of my capacitors and the compressor, so I know in future if I have the same problem is it the capacitors or is it the compressor. This is on my IVT HT+ E9, so your values may differ slightly.

With everything wired up, but the GSHP switched off
Compressor Run Winding 1.5ohms - Terminal 2/N (Common Blue Wire) to 4/T1 (Run Black Wire) on the Danfoss Soft Starter
Compressor Start Winding 2.3ohms - Terminal 2/N (Common Blue Wire) to Brown Wire connected to Run Capacitor (Smaller silver one) (or Terminal 2 on Start Relay)

Capacitors - Check for short circuit. You should get a reading across the terminals which will then rise to open circuit (OL). This is easiest to check by checking between 1/N and 3/L1 on the Soft Starter.

Ah thanks for that will pass it on to my electrician. Funnily enough he was over at the weekend writing details down for the capcitors. We sat there for 2 hours waiting for it to trip - nothing!

Going to replace them just in case though

Oh cool. This is the wiring and parts for mine (yours might be slightly different values). I'll be very interested to see if they are.

Patrol

There's a lot of knowledgable people sharing information here, good to see. Would anyone care to guess what price GSHP's could be manufactured for at volume - are there significant economies of scale or are they always going to be more expensive than a conventional boiler. The inside of my unit didn't look as though it should cost the amount it did, and when they are described as a fridge in reverse I'm left wondering if it's been a captive market or similar.

(I'm not thinking about the ground loop / bore, although having laid my own ground loop I felt this is an area where avoidable costs can be incurred).

beardymarrow

Patrol said:

There's a lot of knowledgable people sharing information here, good to see. Would anyone care to guess what price GSHP's could be manufactured for at volume - are there significant economies of scale or are they always going to be more expensive than a conventional boiler. The inside of my unit didn't look as though it should cost the amount it did, and when they are described as a fridge in reverse I'm left wondering if it's been a captive market or similar.

(I'm not thinking about the ground loop / bore, although having laid my own ground loop I felt this is an area where avoidable costs can be incurred).

Hi, I think the opposite when I look inside mine :-)

The quality of the parts used and the over engineering of every aspect of it, is a beautiful sight. All the MCBs and contactors are quality items from Moeller or Schneider (and there's £250 worth of those in there). The 2 heat exchangers are Alfalaval which can handle 50bar (central heating system operates at 1.5bar) and are probably about £750 each. The compressor is Mitsubishi. It's all really good quality parts. One of the beauties of it is that it is standard parts all connected together (with the exception of the control unit and case).

A fridge compressor would cost about £150 and be approx 150W. The Mitsubishi is 2.8kW and costs approx £2.5k (same sort of cost whether it's for a GSHP or air con unit). So, whilst it is fridge in reverse in concept, it's an order of magnitude more powerful.

Anyway, this might just be me justifying to myself why a GSHP is a good idea :-)

Patrol

No you have the better view, I just see a few bits and can't appreciate what they are. If that means we are unlikely to see comparable prices to boilers that makes me sad as the difference in kW to heat a house between gas / oil and heat pumps is shocking to my inexperienced eye. When our GSHP was installed our plumber was sceptical to say the least but when it heated up a new build house in December within 48 hours he made a comment about heating your house with less energy than a kettle uses. I didn't really understand what he was saying at the time as I had no idea how many kW a boiler used.

beardymarrow

Patrol said:

No you have the better view, I just see a few bits and can't appreciate what they are. If that means we are unlikely to see comparable prices to boilers that makes me sad as the difference in kW to heat a house between gas / oil and heat pumps is shocking to my inexperienced eye. When our GSHP was installed our plumber was sceptical to say the least but when it heated up a new build house in December within 48 hours he made a comment about heating your house with less energy than a kettle uses. I didn't really understand what he was saying at the time as I had no idea how many kW a boiler used.

Yeah, I don't think they'll ever match boiler prices, but then boilers don't match GSHP efficiency :-). I'm sure prices will come down as more companies come into the market and start producing lower end, less reliable parts (such as we see in cheap boilers now), but I don't see them ever hitting the same cost and that's probably not a bad thing.

lstevensuk

beardymarrow said:

lstevensuk said:

beardymarrow said:

Hi,
I was curious so I have just been out to check the resistance of my capacitors and the compressor, so I know in future if I have the same problem is it the capacitors or is it the compressor. This is on my IVT HT+ E9, so your values may differ slightly.

With everything wired up, but the GSHP switched off
Compressor Run Winding 1.5ohms - Terminal 2/N (Common Blue Wire) to 4/T1 (Run Black Wire) on the Danfoss Soft Starter
Compressor Start Winding 2.3ohms - Terminal 2/N (Common Blue Wire) to Brown Wire connected to Run Capacitor (Smaller silver one) (or Terminal 2 on Start Relay)

Capacitors - Check for short circuit. You should get a reading across the terminals which will then rise to open circuit (OL). This is easiest to check by checking between 1/N and 3/L1 on the Soft Starter.

Ah thanks for that will pass it on to my electrician. Funnily enough he was over at the weekend writing details down for the capcitors. We sat there for 2 hours waiting for it to trip - nothing!

Going to replace them just in case though

Oh cool. This is the wiring and parts for mine (yours might be slightly different values). I'll be very interested to see if they are.

Fingers crossed new capacitors get fitted this weekend, the error is happening hourly now!

lstevensuk

Random question - with the IVT heat pump is it possible to mix both radiators and UFH. Currently we have radiators throughout the house. We are building a new extension and wondered if I could have UFH in just the new part?

beardymarrow

lstevensuk said:

Random question - with the IVT heat pump is it possible to mix both radiators and UFH. Currently we have radiators throughout the house. We are building a new extension and wondered if I could have UFH in just the new part?

Yes, absolutely. We have that. I imagine it's fairly common. You need to fit a mix valve operated from the GSHP controller and separate temperature sensor so that the UFH operates at a lower temperature (curve slope is lower). The user manual shows where to fit the valve. 

beardymarrow

lstevensuk said:

beardymarrow said:

lstevensuk said:

beardymarrow said:

Hi,
I was curious so I have just been out to check the resistance of my capacitors and the compressor, so I know in future if I have the same problem is it the capacitors or is it the compressor. This is on my IVT HT+ E9, so your values may differ slightly.

With everything wired up, but the GSHP switched off
Compressor Run Winding 1.5ohms - Terminal 2/N (Common Blue Wire) to 4/T1 (Run Black Wire) on the Danfoss Soft Starter
Compressor Start Winding 2.3ohms - Terminal 2/N (Common Blue Wire) to Brown Wire connected to Run Capacitor (Smaller silver one) (or Terminal 2 on Start Relay)

Capacitors - Check for short circuit. You should get a reading across the terminals which will then rise to open circuit (OL). This is easiest to check by checking between 1/N and 3/L1 on the Soft Starter.

Ah thanks for that will pass it on to my electrician. Funnily enough he was over at the weekend writing details down for the capcitors. We sat there for 2 hours waiting for it to trip - nothing!

Going to replace them just in case though

Oh cool. This is the wiring and parts for mine (yours might be slightly different values). I'll be very interested to see if they are.

Fingers crossed new capacitors get fitted this weekend, the error is happening hourly now!

Good luck. Have you tested the capacitor or compressor resistance?