Potterton 40 boiler

[ntaldar]

Hello,

I have a potterton 40 boiler almost 10 years old. It has got a peculair problem and most of suggestions to change the pcb does not appeal to me. Can someone help me solving the mystery.

This problem appears and vanishes as it pleases.

In the morning when the timer activates the boiler, the boiler goes into a mode where the red and green light flash simultaneously and I can hear clicking sound suggesting that the boiler is trying to switch on and at the same time some parameter is trying to stop it. I then reduce the temperature (temp swicth on boiler itself) to zero and wait for the boiler to click once more. Next I switch on the temperature switch. If it works then fine , if not then I need to bring the temp switch back to zero.This activity is done about 10-12 times and at this stage the boiler works fine for the whole day. I also try to open a few taps in the upstairs bathroom during the whole process just in case if some airlock in the system is preventing the boiler to switch on. This problem may appear for a few days and will not create any problem for months together. Meanwhile, during the summer spell when we were only using the hot water there was no issue. It is only recently when we need the central heating the problem has started.

Boiler giving me problem in the morning suggest that pcb is not at fault as it is cold and most of the times pcb gives problems when the components get heated up.

Any suggestions friends.

 

[MANDATE]

I think you need to establish If your problem relates to Central Heating only and that there are no issues regarding Hot Water. If so I would think it may not be a boiler problem.
Do you have a 3port mid position valve or two 2port valves

 

[ntaldar]

I think you need to establish If your problem relates to Central Heating only and that there are no issues regarding Hot Water. If so I would think it may not be a boiler problem.
Do you have a 3port mid position valve or two 2port valves

Hi thanks for a reply, yes i have a three port mid position valve from ACL Lifestyle 679H340. Do u think that a problem may be with this valve? Any particular reason? Sory for so many questions, hope u dont mind.

Naren

 

[45yearsagasman]

Tell me, is your Potterton 40 by any chance a Potterton Suprima 40?

 

[MANDATE]

If the boiler functions ok for hot water but not for central heating and there is a mid position valve involved then that is almost certainly the cause, especially if CH has not been in use for some time.
The valve may be moving to mid position where you would get both HW and CH but that would only be until HW becomes satisfied. It should then move to CH only but many don't for various reasons.
Time for you read up about mid position valves re testing, stiff spindles, faulty micro switches, faulty motors and incorrect wiring.

 

[ntaldar]

If the boiler functions ok for hot water but not for central heating and there is a mid position valve involved then that is almost certainly the cause, especially if CH has not been in use for some time.
The valve may be moving to mid position where you would get both HW and CH but that would only be until HW becomes satisfied. It should then move to CH only but many don't for various reasons.
Time for you read up about mid position valves re testing, stiff spindles, faulty micro switches, faulty motors and incorrect wiring.

Thank you mandate. I will need to study this and check the valve carefully over this weekend. Will update you with my findings later. Once again many thanks for your advice.

Naren