Helene

Thanks for the advice, happy to give it a try. Should I turn off the pump completely before opening or there's no risk? I see 4 screws on the cover, I guess it's as simple as that? Hopefully...

Thanks everyone for your help - if I wanted to involve my electrician, and with my little knowledge, what should I tell him exactly?

Hi Nick, I've only seen your message now and I still haven't addressed the issue (partly because I've been given a very high quote from a heat geek without having seen anything). When you say "the impact is severe for DHW", in what way? In my mind it's more likely to affect the performance of the heating. If it's not impacting this, I can't complain about more hot water!

I can't know for sure if it's new, as our melcloud wifi controler was only fitted in June, and this allows to see the data with some graphs, and it doesn't go back in time. As we didn't use much heating since, I couldn't notice any issue while the hot water was on but it might have been there from day 1 (a year ago) indeed. As it's not an option to get the installers back, do you suggest I get an electrician or a plumber in first? I think our plumber doesn't want to go anywhere near our heat pump as it can void mitsubishi warranty if he does something wrong... We're in Leeds so if anyone has any local recommendations... Also, what is the impact on heating performance? Is it costing much more, is it reducing the flow? Trying to see if it's an actual big deal or not. Thanks!

It is helpful thanks, though I think I'll definitely need someone to have a look. For a gas boiler it's quite easy, I would just need to get a gas certified plumber out, but for a heat pump it sounds more daunting. I've added two pictures, which I think are valves, do you know which one would be the one potentially related to the issue? As per the controller, I think it wasn't something major, just adding the wifi device so I don't think it changed anything.

Thank you. The heating isn't warm but we had this problem a few months ago (now solved just by changing the lever position). I only realised this new problem since we got the melcloud wifi controler installed. What do you think I should do?

Hello. I've noticed from our melcloud graphs that every time the heating is on, the DHW heats up too. Which I confirmed by touching the flow pipe going into to the cylinder. Is it normal? I'm worried it's affecting the performance of the system and costing us more than it should. We have a mitsubishi zubadan 14W and a unvented cylinder. Thanks in advance for any advice. N.B. the company who installed the system less than a year ago has folded so it's not an option to come back to them.

Hello, I would love to know how you got on with the cover since 2021, and if you had any issue. thanks.

A bit of an update - the boss of the company who sold us the ASHP came around (after bad reviews I left) and agreed that our loft K3 shouldn't have been installed off the 15mm pipe from the room underneath (my office, which is cold). It prevents both rooms from getting a decent flow. So they will reinstall the K3 off another part of the house with 22mm, and help balance the system too. I'll give an update once it's done. Thanks everyone for your inputs so far.

Here is video https://photos.app.goo.gl/8XUp77f5hGCiCPoj8 Hope it helps a bit more. Thanks

I will try to look more closely at the piping, but hard when I'm not used to any of it. maybe a video could help? Very good question - they were supposed to send an engineer two months ago, now it's radio silence - needless to say that I am appalled. I've just sent yet another email to inform them that I'm going to charge them for an engineer visit that I will arrange myself.

I'm unsure it's the case as there was no air for a while when I last bled them, it might be because I've balanced the rads again, changed speed pump, etc.

I hope a few of these pictures help, it's really hard to take a picture as there are pipes in the way. So you think potentially two pumps is over the top? In this case I would think my whole system would be flying but instead it seems feeble.

I tried to change the speed and the flow rate didn't increase indeed. The top floor K3 badly needed bleeding actually (again) - so I was hopeful it was going to sort everything but I still have the same issue. I need to take a picture of the pump, it's a Mitsubishi Zubadan 14Kw. Here is a picture of the system, not sure what these things are called Hopefully it's good enough. I'm puzzled about why one red pump is upside down - I'm sure there's a reason. But they don't seem to be at their maximum, at least one of them. It's definitely something I want to nail indeed. thank you

Very interesting - I did change the speed a month or so ago as it was making so much noise - but didn't notice a difference with the rads. I just wish I remembered if the original flow rate was 40 or the same as now, as I've turned the speed back up to maximum last night but the FR didn't increase at all. I'm wondering if the piping is simply not adequate... though the top K3 does work when the other rads are turned off - not sure what it indicates... I'm desperate for the installer to send an engineer but they ignore me...