Baxi 105HE 60 light flashing

[Backboiler]

Called out to this boiler 475-75-18 today with 60 light flashing on demand for CH or HW. Fan not runnng. Pump proving fault i understand. Pump runs, no air in boiler. The CH differential valve pin is not lifting on demand. I can force the boiler to light by holding up the microswitch. I changed the CH diaphragm, cleaned thepin and greased. Also I made sure the small sensing pipe wasclear. The div valve is relatively clean (no gunge). Still the 60 degreeflashing. I had a spare pump head so changed that just in case. 60 degree neonstill flashing..... I removed large DHW press diff valve to access the front section of the CH valve behind. I then removed the front CH diff pin, cleaned, lubed and replaced. Still no joy. I tried to get the bypass pipe off to check for blockages but it wouldn't budge and I didn't have the O rings, so as time was getting on I went no further .... today. Am I right to assume the entire div valve needs stripping or replacing to rectify the problem? Anyone else had this problem?

 

[REDSAW]

yes, it was a 15min job!!!!! 😉

 

[Billy Bob Bob]

Called out to this boiler 475-75-18 today with 60 light flashing on demand for CH or HW. Fan not runnng. Pump proving fault i understand. Pump runs, no air in boiler. The CH differential valve pin is not lifting on demand. I can force the boiler to light by holding up the microswitch. I changed the CH diaphragm, cleaned thepin and greased. Also I made sure the small sensing pipe wasclear. The div valve is relatively clean (no gunge). Still the 60 degreeflashing. I had a spare pump head so changed that just in case. 60 degree neonstill flashing..... I removed large DHW press diff valve to access the front section of the CH valve behind. I then removed the front CH diff pin, cleaned, lubed and replaced. Still no joy. I tried to get the bypass pipe off to check for blockages but it wouldn't budge and I didn't have the O rings, so as time was getting on I went no further .... today. Am I right to assume the entire div valve needs stripping or replacing to rectify the problem? Anyone else had this problem?

if the 60 light is still flashing and it runs with the rear microswitch pushed up(pin not lifting) the small sensing port under the ch diaphragm is blocked or the pipes leading to it

 

[REDSAW]

14.9 Central Heating Temperature Sensor
(Fig. 69)
1. Ease the retaining tab on the sensor away and
disconnect the electrical plug.
2. Unscrew the sensor from it’s pocket and reassemble
in reverse order. The plug will only fit one way.

unplug it, it might work and should be around 1.5ohms (dry pocketed)
courtesy of gm...

 

[Billy Bob Bob]

14.9 Central Heating Temperature Sensor
(Fig. 69)
1. Ease the retaining tab on the sensor away and
disconnect the electrical plug.
2. Unscrew the sensor from it’s pocket and reassemble
in reverse order. The plug will only fit one way.

unplug it, it might work and should be around 1.5ohms (dry pocketed)
courtesy of gm...

1.5 ohms at 70 degrees,at rest (cold 11k ohms)

 

[Backboiler]

14.9 Central Heating Temperature Sensor
(Fig. 69)
1. Ease the retaining tab on the sensor away and
disconnect the electrical plug.
2. Unscrew the sensor from it’s pocket and reassemble
in reverse order. The plug will only fit one way.

unplug it, it might work and should be around 1.5ohms (dry pocketed)
courtesy of gm...

Wrong in this case Redsaw. Since I last posted the thermistor has been tested, the entire diverter valve has been fitted with the relevant service kits, all pipes are clear but still the damn pin isn't lifting. I'm going back to check the filter on the return pipe and the primary heat exchanger are clear. Can't think of anything else. PCB is only 8 months old

 

[Backboiler]

The return inlet filter and the heat ex where clear. Does anyone else have any suggestions to solve this problem?

 

[Nostrum]

TNT?

Williams & Co have just posted some cracking deals on new boilers!

weird one, sorry I can't help as it sounds like you've covered all the relevant stuff.

 

[Ermintrude]

Glue a 5p coin to underside of lever

 

[Whyme]

Glue a 5p coin to underside of lever

thats my temp' worc diverter valve trick.