Megaflo Systemfit

[Snailer]

Can anyone suggest why my 7 yr old Y plan system has suddenly stopped giving domestic hot water please?

Despite the programmer calling for hot water and central heating when coming on at 7.00am, only the heating comes on - and I have to use the immersion heater to get hot water.

The three way diverter valve never goes to position B to divert to hot water, even when I switch to manual control on the programmer and ask for hot water, but it only goes to the mid position. In fact it only goes to position B if I manually ask for CH & HW and then ask for just CH! It then goes to position B to give me HW! If I then also ask for HW as well as Ch, it goes to the mid position.

The system has never been modified since initial installation, so is as wired by the factory.

Any ideas or suggestions welcomed, please.

 

[clearhead]

pressurised cylinders need annual servicing like your boiler
you can download litrature from heatrae sadia

has
INDIRECT thermal cutout
operated
Check. Reset by pushing
button on cut-out. Check
operation of indirect thermostat

this is linked to motorised valve as a safety measure so reset once or twice
if problem keeps persisting chesck thermostat



motorised valve

 

[Snailer]

Thanks for advice

I have checked red thermal cut-out button - OK

Is the indirect thermostat the little bullet shaped temperature probe pushed down inside the cylinder insulation, please?

How do I check it?

As a check, I have even tried to order one from both Heatrae Sadia and Honeywell - seems it's discontinued by HS, and I can't find a Honeywell stockist of this part.