Air Source Heat Pumps

merlinonline

Some time this afternoon the setting on the timer changed to hot water, and its been like that ever since it says on the display and the actual temp is 61C and its target temp is 65C but like I said its been like that for hours. Not sure why its been on for so long as we don't need to use a large amount of DHW.

Consequently the heating isn't on temp has dropped to 19C which is bearable

Anybody have any ideas?

I have heard that someone else in another village is having difficulty getting the temp to go pass 16C!

albyota

Hi, I would suggest it is trying to do a thermal disinfection, (legionella protection) cycle, it is waiting for the temperature in the cylinder to reach 65 degrees and remain at that temp for a full five minutes before it moves on, you could try turning the whole thing off for a couple of minutes to reboot it, however, it will still need to see the 65 degree tank next time round.

merlinonline

Thanks for that, within ten minutes of posting it went back to heating, I'm wondering if thermal disinfection is going to be the downfall of this system.

albyota

merlinonline wrote: »

Thanks for that, within ten minutes of posting it went back to heating, I'm wondering if thermal disinfection is going to be the downfall of this system.

No, you can adjust the temp down to 60 on the mitsi LCD controller, and turn up the thermostat on the immersion heater, or should I say, get the people who fitted it to do the adjustments.

AL

lovesgshp

Any update on the result Baz@rr ?

Baz@rr

Sorry for not updating before now. After getting out of hospital on Friday my mum proceeded to collapse on Saturday and was rushed back in with blue lights flashing.

The latest news is that we found out why the heating was ignoring the controls and just staying on all the time. I'm not sure what they are called but there are two white boxes on the pipework in the cupboard which I assume are some sort of flow controllers or something. They have a little lever on top which you move left for manual control setting and right for auto. The hot water one was switched to auto - which is how it should be. The heating one was switched to manual, which is apparently an always open mode.

Once it was switched to auto it began to respond to the controls, so that was a step in the right direction at least.

However, I quickly realised the system was still gobbling up the electricity and not actually getting very warm. As a test I set the thermostat on the wall to 20 degrees overnight and took a meter reading.

Next morning I got up and my thermometer on top of the stat was reading 18 degrees and the light on the meter was blinking like mad. I checked the units used - 30 in just over 7 hours.

Last night I switched the heating off at the wall and left a little fan heater on with its stat set to low. I came downstairs this morning and the thermometer said it was 17.7 degrees. Electric units used - 3 in 8 hours.

The plumbers were out today again and it actually worries me that these guys installed the system. I'm pretty sure I know more about it than they do, and it's never encouraging to see an apparently trained professional scratching his head and studying the user manual to a system he installed in the first place.

We did make a breathrough in the end, though, when we realised the fan in the unit outside isn't coming on at all. Thinking about it I've never seen it on, and have always just assumed it must be doing its thing when I'm not looking. Considering I've been at it several times a day, though, this seems unlikely.

They've asked the guy from Grant to come down and check out the system, but am I right in thinking that if the fan doesn't work it's trying to do all the heating using the built in immerser? The fan is one of the most vital parts of a functioning system, surely? If that's the case that would explain why it's devouring the electricity.

I'm not sure why it isn't managing to build up any sort of decent temperature now either, when it was managing to do that last week. I sat my thermometer on top of the radiator itself the other night and the highest it got was 28 degrees.

Oh, and it refuses point blank to produce any hot water. We've been relying on the immerser for that because the solar is still not working.

*Sigh.*

lovesgshp

Thanks Baz@rr.
Best wishes for your mothers recovery. You have enough to worry about with that for sure.
If the fan is not coming on outside, then it does seem to be the immersion unit is running everything. Hope Grant sort it out for you, keep us updated.

Baz@rr

Geotherm wrote: »

Thanks Baz@rr.
Best wishes for your mothers recovery. You have enough to worry about with that for sure.
If the fan is not coming on outside, then it does seem to be the immersion unit is running everything. Hope Grant sort it out for you, keep us updated.

Thanks, much appreciated.

From what I understand the immersion unit in the system is only designed for "top up", would that be right? Hence why it just can't produce the heat required to get the radiators up to any sort of decent temperature.

TiredGeek

Second on wishing a swift recovery

And yes, the immersion heater is designed to top up the heat when the outdoor unit cannot supply enough. It does sound like the outdoor is doing nothing and the immersion is doing it all...

Good luck

albyota

We have three of these in our yard......ripped out for the same reason.