It's a Boilermate A-Class thermal store heated by a Mitsubishi Ecodan heat pump, rather than by a gas boiler.
How does the BoilerMate A-Class Ecodan system work?
Other than the fact that it is heated by a heat pump, in exactly the same way as an ordinary Boilermate A-Class. There is one exception though. The Boilermate used with the Ecodan heat pump has an internal coil for heating domestic hot water, rather than an external plate heat exchanger.
A heat pump is a device that extracts heat energy from the outside air. It uses conventional refrigeration technology to extract heat energy from outside air air blown through it with a large fan. It then raises the temperature of this energy and uses it to heat water, which is then pumped through the Boilermate in just the same way that hot water from a gas boiler is used to heat other Boilermates.
A major drawback of this system is the Ecodan heat pump which needs to be installed in the garden. It is a large grey box about 100cm x 70cm x 40cm, and it contains a large fan so it is not silent!
The reason these systems are fitted is the Building Regulations prevent installation of gas fired heating systems in new homes now, in order to reduce the CO2 output from domestic homes.
Common faults with the BoilerMate A-Class Ecodan system:
1) Water scale-contamination of the internal heat exchanger.
I have to admit I have yet to see this in a Boilermate A-Class Ecodan system but this happens commonly in earlier Boilermates with an internal heat exchanger, so I expect to see it on these systems too eventually (once those installed are old enough). Chemical descaling is perfectly feasible although it is likely to take several hours and several kilograms of descaling chemicals!
2) Circuit board failure.
The board can be interrogated for faults by pressing the buttons on it in accordance with the manual. Unfortunately although the error codes are quite easy to find on the display, the manual doesn't mention what they mean! Any parameter reporting code "29" is an "internal communications error" on the control board, for which the fix is a new control board.
3) Seized water pressure regulator
Here, the symptom presents as no water at all coming from the hot taps. The regulator can be freed but on the one occasion I did this in an attempt to save the customer some money, it seized again a day or two later but in the opposite condition, too high a pressure. So I had to replace it anyway.
4) Failure of the external Mitsubishi heat pump. Tricky, this. I've yet to see one fail but as they use refrigeration technology, I will be unfamiliar should I encounter one. I’ve recently discovered that Mitsubishi support these directly however. See here:
If you'd to discuss your BoilerMate A-Class Ecodan system, call or text me on 07866 766364.
Page first created 10th April 2014
Copyright Michael Bryant 2019
Site first created 21st January 2007
Site last updated 9th March 2019
Gas Safe Register 197499. CIPHE reg no 56207