Mitsubishi ASHP, hot water tank and system
I have a Mitsubishi ASHP, hot water tank and system installed at my property which was installed around July 2023. Generally, we have been very happy with the system. I pay over £300 per annum to have Mitsubishi service the whole system annually. On the first maintenance visit in 2024 they identified a few minor issues with the installation which the original installer resolved without issue. On the second visit in June 2025 no issues were identified and I did not receive any kind of report associated with the visit. In Oct 2025 one of the main pumps (which is covered by the warranty) started making a loud and obvious noise. I contacted Mitsubishi and sent them a video of the issue and they refused to attend unless I paid £309 even though this is under warranty. They claimed this would be refunded if this was a warranty issue. Following the visit on 4th Nov 2025 Mitsubishi claimed that we had 'tampered' with the settings since the maintenance visit(s) and increased the pump speed and partially closed an isolation valve and that this had caused the noise issue and hence it was not a warranty issue. We had no reason to ‘tamper’with any settings, wouldn't know how to and had not touched anything within the cupboard which we do not even open regularly. With their adjustment the noise went away for a couple of days but returned and I sent another video to Mitsubishi on 11 Nov 2025.
After a lot of chasing, they finally returned to look at this again on 9 Dec 2025. At that visit the engineer said Mitsubishi had reported a number of similar problems with a number of pumps and whilst on the phone to the relevant department they told me Mitsubishi had agreed to replace the pump under warranty. I confirmed this in writing to Mitsubishi on 15 Dec 2025 as I had heard nothing from them to arrange the return visit to replace the pump.After numerous chases I received a report from the 9 Dec visit on 27 Jan 2026 which bore no relation to our problem or the discussion with the engineer. It even referred to a system of a different kW output and a hot water system when our problem was related to the heating system. This report was clearly not ours and a mix up had been made. I immediately made Mitsubishi aware of the issue. Since then I have been chasing for a response regularly but now I get nothing but radio silence. The issue with my pump is not resolved and the annual maintenance visit that I pay for is clearly worth nothing if they then just blame genuine problems with components on the end user by claiming they have altered the settings. I am disgusted with this behaviour and lack of accountability and service. I remain out of pocket for an additional £309 which has not been refunded.