Boiler re-lighting problem

[ibee]

Hi all, we have a fairly old ideal classic FF260 , recently serviced. It fires up when Called to in the evening. However it won’t relight during the course of the evening when heating is called for. I fitted a new programmer but it didn’t cure the problem. The 3 way valve seems to work ok. What does work though is turning the system off at the mains and then turning it on again. The boiler then immediately lights. Would greatly appreciate any ideas, I’m wondering if it could be the pub in the boiler

 

[terryplumb]

More likely the mid position valve ( 3 way valve as you call it)

 

[Madrab]

could be the pub in the boiler

Must be some size of boiler - mine's a pint.

 

[ibee]

More likely the mid position valve ( 3 way valve as you call it)

Yes, it did cross my mind it could be that but every time I've had to 'Turn off,turm on' the system the valve is always in the correct position for satisfying heating. Have also tried checking movement of valve for different situations: hotter /colder room and water needs and the valve always behaves as it should. My thoughts were that maybe a component on the boiler PCB was having an intermittent hiccup. Dont know if this throws a different light on things but i'll welcome your reply

 

[terryplumb]

There are microswitches within the valve ,and even though the valve motor works ,and positioning moves,the switches may not.
Testing voltages present at the wiring centre would establish if the valve is at fault.

 

[ibee]

There are microswitches within the valve ,and even though the valve motor works ,and positioning moves,the switches may not.
Testing voltages present at the wiring centre would establish if the valve is at fault.

Thanks Terry I'll give it a check

 

[terryplumb]

In a nutshell ,when programmer and thermostats are calling for heat the MPV sends voltage through its orange wire to the boiler. If no voltage at the orange wire in the wiring centre boiler can't fire up. If voltage is going to the boiler and it doesn't fire up it's a boiler issue.

 

[ibee]

In a nutshell ,when programmer and thermostats are calling for heat the MPV sends voltage through its orange wire to the boiler. If no voltage at the orange wire in the wiring centre boiler can't fire up. If voltage is going to the boiler and it doesn't fire up it's a boiler issue.

Hi Terry, just noticed the rads werent working but should have been.I checked for voltage and got a reading of 4. Turned system off and on again and boiler started straight away with a voltage of 229

 

[terryplumb]

Was the programmer also calling for the hot water cylinder to be heated ?

 

[ibee]

Was the programmer also calling for the hot water cylinder to be heated ?

Think it was

 

[terryplumb]

The boiler would have received the voltage directly from the cylinders stat. Your MPV is faulty.

 

[ibee]

Many thanks Terry, will change it tomorrow

 

[terryplumb]

Before you do ,worth checking other voltages to rule out thermostat / programmer issues, although it's very likely the MPV.

 

[ibee]

Will do but I will get a new actuator anyway and fit it If it still happens I can always return it if I wish to and it eliminates (or cures) the cause. Again many thanks for your help