‍Boilermate A-Class:

‍

‍

‍How does the BoilerMate A-Class work?

‍

‍A conventional central heating boiler heats the water in the BoilerMate directly. The stored water is pumped to the boiler for heating and back again by one of of the three pumps behind the front panel of the unit whenever the stored water temperature drops below a specific temperature set in the factory. A second pump pumps this pre-heated water around the radiator circuits when central heating is required. 

‍

‍The BoilerMate A-Class delivers hot water to the hot taps in a similar way to the previous BoilerMate III ands 2000 models, but without the user-adjustable thermostatic blender valve. A third pump starts when a hot tap is turned on and pumps hot store water through the plate heat exchanger, thus heating the cold mains water very effectively on its way to the hot taps or showers.

‍

‍The operation of the appliance is controlled by an unnecessarily complicated and poorly (in my opinion!) made printed circuit board which also records certain functional errors and returns them when interrogated.

‍

‍  

‍

‍Common faults with the BoilerMate A-Class:

‍

‍Surprisingly there are very few. Most of the problems with the Boilermate 2000 and preceding models have been ironed out. I get very few calls for the Boilermate A-Class which probably explains why it took me so long to write this page :) These are about the only faults I see on an A-Class. Most other apparent faults turn out to be failure of the gas boilers heating them. Incidentally the Boilermate A-Class is often installed with Gledhill's first conventional gas-fired boiler, the GB10, GB20 or GB30. As usual, these are designed in a manner most heating technicians find perplexing but they are straightforward (usually) to fix. I'll write and publish a website for the Gledhill GB10-30 gas boiler soon!

‍

‍

‍1) Water scale-contamination of the plate heat exchanger:

‍

‍The plate heat exchanger was hailed by manufacturers as the answer to water scaling, but this has proved not to be the case. Hard water in certain areas still seems capable of blocking a plate heat exchanger with calcium deposits causing restricted hot water flow from the taps and warm (instead of hot) temperatures. When the problem becomes acute the water flow slows to a trickle and the temperature swings wildly from scalding hot to stone cold. The answer is to fit a replacement plate heat exchanger, which takes around an hour (instead of several hours to de-scale the copper coil heat exchanger in early versions of the BoilerMate).

‍

‍ 

‍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) Diverter valve jamming:

‍

‍There is an electric diverter valve on the Boilermate A-Class and the Systemate A-Class which switches the water from the boiler to either the radiator circuit for central heating, or to the Boilermate thermal store for hot water. This diverter valve is moved to the CH position by an electric motor but is moved back to HW position simply by a spring. This valve grows stiff with age and the spring ceases to be strong enough to return it fully to HW position. When this happens, the radiators continue to heat up even though the central heating controls are set to OFF. The electric valve head can be removed and the mechanical part of the valve exercised manually to free it off but sometimes the stiffness returns and a longer-term fix is required. In this case the boiler circuit needs to be drained down and the whole valve replaced. Either with another Danfoss brand valve the same as the original, or with a different brand of diverter such as Honeywell or Drayton. Sadly there are no brands of valve that are particularly reliable in the long term. All tend to fail in one way or another do probably the Drayton is the best option to choose as the head on this valve unclips quickly and easily without tools (unlike the other two brands), making freeing off a stiff valve spindle quick and easy.

‍

‍

‍

‍

‍If your Boilermate A-Class has stopped working, do call or text me to discuss a repair. The best way to reach me is to text message me on my mobile, 07866 766364.

‍Menu:

‍Boilermate A-Class installed in a house in Bracknell, Berkshire