Air Source Heat Pump error messages

Fatferds12

We've got a Danfoss DHP AQ air source heat pump which has stopped working and is showing 2 error messages which are

Comm Error HP Card - Communication broken between display card and heat pump card (outdoor)

Comm Error Exv Card - Communication broken between display card and expansion valve control card (outdoor)

We've tried the obvious turning on/off but that hasn't worked.  I contacted Danfoss and they just said to find somebody local that could help or look on Checkatrade but we've had no luck. 

Any help or advice would be good.

matelodave

One would have hoped that Danfoss could have put you in touch with your local/nearest agent. However failing that, I got a a list of three heat pump installers within 10 miles of where I live from just typing in this "air source heat pump engineers near me" and if I stretch the net wider then there are even more, including the company who actually installed mine who are 30 miles away.

You could try here as well - https://www.homeadvisor.com/near-me/heat-pump-repair/

Fatferds12

We finally had somebody come out today and fix the pump - hooray!  Mice had chewed through the communication cable (CAT6) on the outside wall that goes to the outside unit and it also looked like they'd been nesting in the insulation.  Next stage is to box in all pipes and make it mouse proof..............

matelodave

It's hard to credit that sort of problem and it really does need someone who knows what they are doing rather than just changing everything in sight.
Glad you got it sorted. BTW how or where did you find your saviour

Fatferds12

I tried the links you put up but they didn't come up with anyone near me and so in usual Internet fashion I went off down different links and found them.  They're only about 5 miles from us but not easy to find on the Internet.  Thanks for suggesting the link as although it didn't work directly at least we finally found someone.  We live in West Wales and even though a fair number of people have air and ground source heat pumps the engineer said there aren't that many companies that fix them.  

matelodave

I live in Cambridgeshire and we seem to have a few around but they weren't a lot of help. I had a fault on mine which kept shutting it down a couple of days before Christmas but I couldn't get anyone out to until the New Year ( I've still not got a date for when someone is coming but its not urgent anymore).

However, as it failed completely on Christmas Day and the fault code pointed to the flow switch I decided to sort it myself. So on Boxing Day I drained the hydrobox, removed and  cleaned the flow switch and put it back together - it's been fault free ever since.

Fatferds12

Well you obviously know what you're doing so maybe you should go into the heat pump business yourself!  If you fancy moving to Wales there's plenty of business for you although by the sounds of it Cambridgeshire needs you just as much as here!  

matelodave

Nah, I dont really know what I'm doing but I'll have a go at most things whatever it is, although I tend not to pull the car to bits anymore.
The days of lying underneath it in the pouring rain are long gone and some of the technology has gone beyond my capabilities, tools and testers.. Domestic applienace are still OK though

Fatferds12

I used to work for the RAC and the mechanics said how much it had all changed.  They used to go out and fix a car at the roadside but as cars got less 'mechanical' and more 'electrical'  they knew that 9 times out of ten they just need to take a trailer to get it to the nearest garage and where was 'the fun' in that.  Thanks again for your help.  Take care