Alpha cd32c hot water for 10 secs

[DAZZA6432]

Hi all
i had a problem with the bolier indicating 2 fault lights A flashing B continuosly, stripped down the diverter valve and removed some hard limescale, cleaned out, refitted valve and now heating is sound only problem remains is when i turn on hot tap boiler ignites but after 20 secs the same fault lights return, turn off tap and boiler returns to normal after 30 secs???????????? would appreciate any advice.

thanks

 

[Napper]

flashing B is overheat,
can be reset by turning selector nob. MIs sudjest blockage in pipework.

 

[Napper]

among other things...

 

[diamondgas]

:welcome: dazza to the forum🙂

Initialy it sounds like your plate heatex may also be "scaled" up? Do you live in a hard water area?

 

[Hardy1]

check the spark gap. if boiler firing then turning off e,t,c.

 

[Alpha man]

Are you sure you have the fault lights right?

If the A is on constant and B is flashing it will be the Temp sensors.

 

[DAZZA6432]

Yes i do,could the dhw heat exchanger or hot water outlet be partially blocked?

 

[diamondgas]

Yes i do,could the dhw heat exchanger or hot water outlet be partially blocked?

If you're saying "yes I do.." to living in a hard water area and you have discovered Scale within the diverter section in all likelyhood it will also be throughout your domestic water system, plate heatexchange included.. Do you have any scale reducers fitted?

Don't rule out other possible's such as sensor faults etc. By-the-way ... this is just one possibility 🙂

 

[Alpha man]

Yes i do,could the dhw heat exchanger or hot water outlet be partially blocked?

Yes the DHW do scale up, esp if you are in a hard water area or you have dripping hw taps in doors.

 

[DAZZA6432]

The plate heatexchange was blocked with scale, de-scaled it and all is good thanks for the help