Heat pump belly up. Now what?

[Bobster.]

My 13 year old Kwikot ran as usual yesterday. It did not run at all today. The display is dead. I don’t want to peuter, but I do want hot water fairly pronto.

I have established that the unit does get power (even I can use a multimeter)

I can get Kwikot in. They’ve already told me that there is no fixing this model. So that will be a new installation, effectively from scratch.

I could go for another brand, but I suspect that other than ITS they are all the same. And again it will be an installation.

Third option, and maybe the quickest to implement, is to reconnect the element that is still in the geyser. Put that on a timer so it doesn’t draw from the battery at night. But is this a long term solution?

It’s a 200l geyser. I suspect the element in there is 4kW, so that will need downgrading. But I expect that a 1kW will need to run a long time, whilst 2kW is more than the pump draws, so I get closer to overloading. Ok…i can move it to non-essentials.

Inverter is a 4.6kW Goodwe ES.

[Bobster.]

6 minutes ago, Bobster. said:

I could go for another brand, but I suspect that other than ITS they are all the same. And again it will be an installation.

No. For a start, Kwikot is not Kwikot anymore.

ITS, if I read correctly, has a plastic casing. Hmmmm... If I use the same location it is north facing and will get a lot of sun.

Kwikot's specs quote a slightly lower sound level, and I want to give my neighbours some thought. But it is minor. Most say 55db, Kwikot say <52.

 

Edited September 8 by Bobster.
Sppelimg

[TimCam]

Sorry to hear of the demise of your  heat-pump, but 13 years for a mechanical device now-days is not too bad.

Like you said, just to have a warm shower for the next few days connect your geyser element (hopefully not 4 kW), while you look around for a replacement.

You have nothing to loose, why not strip the heat-pump and poke around. Maybe just a normal fuse or thermal fuse blown, or something else simple?

Always something to help you empty your wallet.

[Bobster.]

46 minutes ago, TimCam said:

You have nothing to loose, why not strip the heat-pump and poke around. Maybe just a normal fuse or thermal fuse blown, or something else simple?

It was serviced 3 months ago. Guy cleaned out the strainer and told me that they don't fix them anymore. Though I suspect it's the electronics. I traced the 230v to the PCB and made sure everything was securely fastened. There's a conventional fuse in there (glass cylinder with a filament) and that's intact. 

I don't know what a thermal fuse looks like, and I don't have the tools nor can I find a circuit diagram. They just show you the connections to the PCB. There's an LED on it which is dead, so I'm thinking power supply or something pulling it down. 

52 minutes ago, TimCam said:

Always something to help you empty your wallet.

Ain't that the truth! 

There are kwikot appointed techs operating in this area, but I suspect that for them an installation is less hassle and more money than fault finding. 

Also because it uses a now banned (or discouraged) gas, they don't change the compressor or the motor or regas it. But maybe they can find a PCB. 

The new ones have a different gas and you control them via a smartphone app, but current consumption is the same, which is disappointing. 

I bought a new deep freeze last year. Bigger capacity, yet it uses literally a third of the power the old one did. Heatpumps (not just Kwikot) don't seem to have made the same gains. 

[P1000]

11 hours ago, Bobster. said:

Heatpumps (not just Kwikot) don't seem to have made the same gains. 

That's because most of the efficiency gains for fridges/freezers come in the form of better insulation. (And the door seals also contribute significant losses as they age).

[Scorp007]

15 hours ago, Bobster. said:

 

I bought a new deep freeze last year. Bigger capacity, yet it uses literally a third of the power the old one did. Heatpumps (not just Kwikot) don't seem to have made the same gains. 

 There are some heat pumps that are having a COP of 6 but cannot remember which make or size. Much higher than my COP of 3. These were installed at an old age home. 

[Bobster.]

On 2024/09/08 at 11:21 PM, Bobster. said:

There are kwikot appointed techs operating in this area, but I suspect that for them an installation is less hassle and more money than fault finding. 

Sinner! Slanderer! Repent.

They came out this morning. Were here about 10 minutes. There is a transformer that steps down the AC before feeding a bridge rectifier which then gives power to the PCB. The transformer had gone. They had a spare in their van. They also tell me that they still have complete PCBs available, and if it wasn't the transformer then Kwikot would have quoted me on the PCB replacement.

What they won't replace on mine (13 years old) is anything to do with the gas, which is now regarded as a greenhouse gas. So compressor, condensor etc or an actual regas. But they do still have spares for the electronics (or the electronics haven't changed in 13 years).

Anyway, they did troubleshoot and repair.

[Bobster.]

On 2024/09/09 at 10:34 AM, P1000 said:

That's because most of the efficiency gains for fridges/freezers come in the form of better insulation. (And the door seals also contribute significant losses as they age).

I think there's more to it than that. I measured my old deep freeze with a kill-a-watt. Then we got the new one, and once it was up (down?) to it's regular running temperature I measured that one too. 

Old

Total: .577 kWh
Low: 11.1 W
Peak: 1365 W

New

Total 0.192 kWh
Low: 2 W
Peak: 107.8 W

Both sets of figures are for 8 hours of operation. The new freezer is larger by 70l.

So the new one's motor doesn't draw as much, especially when starting up. 

Edited September 10 by Bobster.

[Scorp007]

5 hours ago, Bobster. said:

Old

Total: .577 kWh
Low: 11.1 W
Peak: 1365 W

New

Total 0.192 kWh
Low: 2 W
Peak: 107.8 W

Both sets of figures are for 8 hours of operation. The new freezer is larger by 70l.

So the new one's motor doesn't draw as much, especially when starting up. 

Very interesting to see the difference in peak start power between the 2 units. 

[TimCam]

10 hours ago, Bobster. said:

Sinner! Slanderer! Repent.

They came out this morning. Were here about 10 minutes. There is a transformer that steps down the AC before feeding a bridge rectifier which then gives power to the PCB. The transformer had gone. They had a spare in their van. They also tell me that they still have complete PCBs available, and if it wasn't the transformer then Kwikot would have quoted me on the PCB replacement.

Lovely to see you can have a hot shower again. Thumbs up to the Kwikot technicians willing to help with "old" equipment.

[zsde]

20 hours ago, Bobster. said:

Both sets of figures are for 8 hours of operation.

Mind sharing make and models of the two freezers?
 

[Bobster.]

7 hours ago, zsde said:

Mind sharing make and models of the two freezers?
 

The old one was a Bosch. I can't give any more details because it is now in Zimbabwe. It was rated A+ under whatever system was in place when we bought it.  Point, for me, is that it was several years old and so I attribute the improvements in performance to advances in technology.

New one is a Samsung RZ32... something.
 

Edited September 11 by Bobster.