No hot water.

[Asare Thagu]

1. Hi I have a potterton suprima (41 607 77) old and small boiler. It was working fine but now a days when i turn off the central heating and keep on the hot water mode only the boiler does not fire up. All i can see is the yellow light flashing on the boiler. Grateful if any one can advise what is causing this problem on my boiler.

 

[diamondgas]

Sounds like an external control issue 1st thoughts. Do you know what a diverter valve or zone valve is?

 

[jtsplumbing]

Same as diamondgas ! if boiler is working ok for heating, its got to be someother control, Programer - Diverter valve - Cylinder stat that is causeing the fault.

 

[Asare Thagu]

Same as diamondgas ! if boiler is working ok for heating, its got to be someother control, Programer - Diverter valve - Cylinder stat that is causeing the fault.

I think diverter valves are working fine as I can see the leavers moving when turning on/off CH and DHW mode switch. Don't know how to check the cylinder stat. It looks ok as it is set at 60c.

 

[diamondgas]

Have you no hot water at all? If the valve is moving but the boiler isn't lighting then the issue is most probably the valve actuator? You have two yeh, one for heating and the other for hot water?

 

[Asare Thagu]

Have you no hot water at all? If the valve is moving but the boiler isn't lighting then the issue is most probably the valve actuator? You have two yeh, one for heating and the other for hot water?

Only when I keep in the CH and HW mode I can have hot water, but if I turn the CH mode off the boiler won't fire up. I can see the it is on demand as pump and fan runs for few mis but boiler won't fire. Is has two diverter valves one for CH amd other for HW.

 

[diamondgas]

Do you have hot water? ........ On hot water only try turning your cylinder thermostat up and see if the boiler fires up! Do you have hot water???

I'm wondering whether your hot water is already satisfied hence the question ... may sound thik but i ain't at your hoose!!!

 

[jtsplumbing]

Is it possable that the water level in system is to low and not pumping through coil ? have you got water in small tank in loft ?

 

[Asare Thagu]

No hot water in the cylinder! Water circulates through the coil only when CH and HW mode selected together. When I turn off the CH and use up the hot water it won't fire up again to heat the water in cylinder.

 

[mountainman]

May be faulty microswitch in DHW motorised valve.

 

[Asare Thagu]

Thanks guys, now i have hot water. The fact is i don't know yet how it fixed. All i did was just played with components and connections.

 

[mountainman]

Hee hee, basically that's all we do

 

[diamondgas]

Thanks guys, now i have hot water. The fact is i don't know yet how it fixed. All i did was just played with components and connections.

I'd note mountainmans advice for when it next goes off. maybe get yourself a spare actuator for the eventuality