Hot Water Problems

I have a problem with my hot water. It starts off hot and eventually goes luke warm. I have checked the temperatures and indicators on the ACB and it seems that the heating pump is not switching off (the heating pump green light stays on) when the thermal store temperature goes below 64 degrees as it says it should in the manual. In fact, even with the thermal store temperature below 50 degrees, the heating pump stays on.

Am I correct in assuming that this is an ACB problem or could it be something else? Is the ACB repairable or do I need to replace it? Can I get an ACB for less than £194.50+VAT?

I notice your post morphs seemlessly from a hot water problem into a heating problem!

First the HW prob. This is probably because the HW pump is failing to start. Usually a sensor problem. Could alternatively be that the pump IS running but the heat exchanger is scaled up.

Now the CH problem. On a Sytemate 2000 the 'heating pump' has two functions. In addition to heating the rads, IIRC it also circulates water from the boiler into the store when the store temp is low, therefore I'd expect it to still run when the store temp is low!

For your last question, I can supply you with an ACB board for £194.49+VAT if you are really stuck... ;-)

Alternatively you can get an ACB board for £189.01+VAT here: http://www.segel.co.uk/


Cheers, Mike

Thanks for the reply. Actually I haven't got a heating problem; it's working fine. In the Systemate version I have (SM225) the boiler and heater pumps are separate and have separate LEDs indicating when they are on, and there is a third pump for the hot water heat exchanger. According to the manual, the heater pump should go off when the thermal store temperature goes below 64 degrees while there is a demand for hot water. The question I need answering is whether this function is controlled by the ACB. And can ACBs be repaired?