Power supply
ASHPs have a PCB just like a computer. And they can also be damaged by a "spikey" mains electrical supply.
This has been my experience living in a rural area where power cuts (from a few seconds to a few hours) are not uncommon and the supply generally suffers surges.
After 4 years of operation the PCB in my pump packed up. It required a £650 replacement.
I have now fitted a surge suppressor at the fuse board. This protects the entire house (although doesn't prevent power cuts).
It was under £200 to have the work done. Astonishingly these are still only recommended, not required, by the building regulations when the wiring is put in a house.
I'd strongly recommend you fit one if you have a heat pump. It will protect it and any other sensitive electronics in your home.
Grant Aerona HPID10 10kWh ASHP
Thanks for the tip Mike. I’ll look into this. As for building regs, they’re all over the place, and a lot of stuff doesn’t make sense.
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One of the first questions ASHP installers check, is your electric supply. I am lucky to have a home built in 2001, rural, with a step down transformer on the small Estate where I live, an underground supply and a 100A circuit to my home.
I was not aware of the issue Mike P raises on this post, but will enquire. Power cuts are a very rare thing now, compared to when I first moved here 20 years ago and power would go off every few months, for hours. Sorted when they put a new cable in back to the mains distribution network to the Estate.
But I would recommend anyone considering an ASHP to open their meter cupboard and check the supply fuse - 60, 80 or 100A? Or you may be lucky have a 3 phase circuit in the UK. But older properties in towns/cities could even have shared lines - 60A between two properties. This will potentially prevent you having an ASHP or an EV charge point. Your DNO will need to upgrade the circuit. I would hope not at your cost.
Daikin Altherma 3H HT 12kWh ASHP with Mixergy h/w cylinder; 4kW solar PV with Solic 200 electric diverter; Honda e and new Hyundai Ioniq 5 N electric vehicles with Myenergi Zappi mk1 charger
We also fitted a surge protector on the main board at the recommendation of the plumber working on our extension as he worked on a job where someone had a large repair bill from an electrical surge damaging their ASHP system.
Mitsubishi Ecodan 14kw ASHP + 500l Cylinder
Posted by: @juliancBut I would recommend anyone considering an ASHP to open their meter cupboard and check the supply fuse - 60, 80 or 100A? Or you may be lucky have a 3 phase circuit in the UK. But older properties in towns/cities could even have shared lines - 60A between two properties. This will potentially prevent you having an ASHP or an EV charge point. Your DNO will need to upgrade the circuit. I would hope not at your cost.
A caveat that most houses have a maximum 100A cutout (fuse) carrier but it doesn't tell you what fuse is inside. There may be a note on it indicating what's inside, or there may not. Only an electrician (and technically only the DNO) can pull the fuse to check (the fuse has DNO seals and the person pulling it is supposed to wear specific arc flash PPE).
If you're on a 60A or 80A fuse the DNO may upgrade for free if the cabling is up to scratch, but may charge if remedial works are needed to your meter tails or to the incoming cable. First port of call is the DNO who can come out and advise.
Prunus is absolutely right. I’m ONLY looking in the meter cupboard and reading the label. Get a qualified electrician or as you say - DNO very helpful, and responsive in Worcestershire to confirm.
Daikin Altherma 3H HT 12kWh ASHP with Mixergy h/w cylinder; 4kW solar PV with Solic 200 electric diverter; Honda e and new Hyundai Ioniq 5 N electric vehicles with Myenergi Zappi mk1 charger
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