Alpha 280p - Heating but no hot water......help pls

[Simon75]

Hi,

My Mums Alpha 280p is fine with heating but won't give out any hot water.

I have stripped down the front diaphragm and primary diaphragm and lubriacted/cleaned and they seem to move fine in and out and make contact with the microswitches, but when put back together it has made no difference.

There is heat at the secondary heat exchanger but it isn't going down the hot water pipe.

Have i missed something obvious?? Would appreciate any help.....

 

[mrgas]

Does the micro switch make?
Have you tested it electically?
The microswitches can fail as well as the diaphram.

 

[Simon75]

i only tested the dhw microswitch for continuity and it was ok, didn't think to test the primary microswitch???

 

[mrgas]

primary microswitch is working fine if the heating works.

 

[mrgas]

Temporarly link the green wires together and see if pump/fan comes on.
Think they are mains voltage so watch out!

 

[Simon75]

ok, struggling.

Do you know if there any other bits i might or would need to look at? Could there be a blockage somewhere??

 

[mrgas]

Try the above.

 

[Simon75]

I'll give the green wires a go, not at the boiler now but are there only the two sets of green wires?

 

[mrgas]

The green wires going to the domestic flow switch.

 

[Simon75]

Ok, sorry to be dumb. If they both come on, what will that tell me? Thanks again for your help