Apollo 15/30 Boiler

[timetrialer]

Can anyone shed some light on the problem I have with my Apollo 15/30 boiler.It works ok water and heating,but the problem occurs when the heating goes off on temp it will then make noises and then knock the pilot light off. I changed the limit stat(connected to the thermocouple)thinking this would cure it , but the problem still exists. I would be grateful if anybody can help ?

 

[avidfan]

Does the pump continue to run after the boiler has shut down? If not then maybe a problem with pump over run. (This dissipates heat from boiler when shut down)

 

[timetrialer]

Thanks for the reply, but the pump does still keep running for a short while after the boiler shuts down.
Sorry I am wrong it must be the pump overrun, because the pump actually does stop straight away once the boiler goes off on temp. Do you know what could be stopping the pump over running. There is a stat on the boiler and I have tried that in all 3 positions ie. Low, High and off, but it makes no difference.

 

[Gas2Air]

If the pump and pump overrun operation are ok your heat exchanger has scale inside, needs replacing or flushing. Or get a modern boiler!!

 

[timetrialer]

Thanks for that Gas2air. You might be right to go for a modern boiler, because it is 24 years old now. I did think I could get another few years out of it !!! What would you suggest to replace it like for like ?

 

[riorob]

I have a Thorn Apollo wall mounted boiler. The pump would stop while the boiler was alight so it would bang and then cut out on the overheat interuptor stat. This is on the left hand side of the boiler and is attached to the thermocouple with 2 wires. I think you have the same problem as I had. If you take the inner cover off your boiler so you can see the pump overrun stat. If its faulty it will stop the pump running at any time. This stat is in the bottom right hand corner and looks like a round disc held by 2 screws. There are 3 wires attached to it and it is very easy to change. It costs £10 from heating components ltd. You would be well advised to change the thermocouple and the mantle jet so that you keep your pilot light on. The mantle was £7 and the thermocouple about £10. The Apollo is a great little boiler and I have had mine for 18 years.
Best of luck.

 

[kevplumb]

err check the date of the post

ohh btw welcome to the plumbers loony bin

 

[riorob]

Yeah I know but the information may be usful to another unfortunate person. Thats why I posted. Its bad enough that you have no CH or DHW but a nagging wife as well?

 

[timetrialer]

Hello riorob,
I have changed the interuptor stat attached to the thermocouple and the pump overun stat, but it is still knocking the pilot light out when the heating goes off. I know there is two temp stats on the flow pipe, perhaps I should change these, because it doesn't make any difference when I alter the high/low stat on the boiler.
I am just eliminating things now. Maybe the 3 way valve could be sticking ?

 

[pannierstan]

Hello riorob,
I have changed the interuptor stat attached to the thermocouple and the pump overun stat, but it is still knocking the pilot light out when the heating goes off. I know there is two temp stats on the flow pipe, perhaps I should change these, because it doesn't make any difference when I alter the high/low stat on the boiler.
I am just eliminating things now. Maybe the 3 way valve could be sticking ?

Have you checked the pilot top socket as was suggested earlier?
Failing that did you check the pump overrun with a match underneath it to see if it actually does bring the pump on!(With the system cold and clock turned to off) It might be wired wrong.

Stan