Alpha C27 DHW problem

[Don262]

Can I have some advice from you good people.

I have a 4 1/2 year old Alpha C27. CH is fine but DHW is intermittant and when is works has a very low flow of 2.25 litres a min. I've read the other similar posts on here, and so checked the cold water inlet filter (completly clean) and had the DHW flow valve off which seems fine ( and does work intermitanlty ). Someone has offered the advice that it may be a 'scaled up heat exchanger' and I do live in a hard water area. The other posts mentioned a diaphram but I didn't see one when I had the flow switch off, and would that give a very low level of DHW.

Thanks for looking.

Don262

 

[gas4you]

These combi's don't work with a diverter valve and diaphragm, hence why you didn't see one. You also don't have a plate HE either.

It could be scale in the domestic side of the HE, reducing the flow, but then I would expect the boiler to probably overheat as well.

As you say your flow switch works intermittently, I would replace this first of all, then look for the cause of the flow restriction.

 

[mickyg]

if it is as dave suggests a biflo heat exchanger(don't recall seeing this particular boiler) then this is prob gonna be your problem(scaled up). Most flow switches need at least 2-3 l/min to operate so that would be why its not working.