bosch 280 boiler fires up then cuts out

[hayabusa1300]

hi boiler if i put on all time fires up pumps runs then gas ignites runs for about 13 seconds then gas goes off pump is still running
hot water no problems with nice and hot and gas ok
its just central heating side of it not working gauge shows 2 bar water pressure reset button never needed resetting any ideas thanks wayne

 

[malkie]

Is it trying to fire up again itself if you leave it or do you have to turn it on and off,if it keeps trying then it may be that the flow switch isnt operating properly

 

[hayabusa1300]

yes trys to and does same thing where would flow switch be located i gather its on water pipe and has 2 wires connected to it 2 red wires

 

[hayabusa1300]

hi seen valve on pipe work with 2 red wires gather that does flow i toke wires off and tryed run it did same cuts out yet hot water side works perfect

 

[stucky]

flow switch is for water only so its not that.pressure should be 1bar when cold.check water pressure switch

 

[hayabusa1300]

going ask stupid ? where is it and how do i check it i am a motor mechanic
but with your help sure i can sort problem out if water pressure was too high would that cause this problem thanks for help

 

[hayabusa1300]

other thing just noticed when it is turned off after while it trys well seems to start pumping but doesnt try ignite that is with out it turned on via control in the off position

 

[Gas2Air]

other thing just noticed when it is turned off after while it trys well seems to start pumping but doesnt try ignite that is with out it turned on via control in the off position

Have you been drinking?

 

[hayabusa1300]

nope heating on standby , not set on demand and pump kicks in but doesnt try ignite yet hot water side works fine

 

[Gas2Air]

nope heating on standby , not set on demand and pump kicks in but doesnt try ignite yet hot water side works fine

Is the diverter valve moving or in CH position fully? Check by observing valve head spindle moves, run HW and lever should move to A position, turn off tap, and lever should move to B, with CH demand.

Sounds like CH sensor probably got water on it or failing though.

 

[Agile]

I have encountered a fault on these where the CH does not work which was caused by the PCB.

Momentarily disconnecting the CH sensor did cause it to fire up until it reached the set temperature though.

Tony

 

[hayabusa1300]

divert valve ?????????????/ if you could give clue where it is and what looks like i have looked under neath seems big brass collection of valves one with red handle gather that over flow as i found out when turned it and water went out side any plumbers in chorley area ave quick look dont want ripping off plumbers from hell job lol

 

[Gas2Air]

divert valve ?????????????/ if you could give clue where it is and what looks like i have looked under neath seems big brass collection of valves one with red handle gather that over flow as i found out when turned it and water went out side any plumbers in chorley area ave quick look dont want ripping off plumbers from hell job lol

If you take off white front panel, you will see a red expansion vessel, get a torch and look behind that towards the back, normally a creamish ACL valve head, you should see a black nipple lever on its side that moves up and down upon HW/CH demand.

 

[hayabusa1300]

i see red tank vessell at left hand side at back see white type tank side of that i see is it gas valve i will check tomz wit htorch see if can see divert valve thanks

 

[hayabusa1300]

hi found valve you was on about was black lever hanging down loose so i pushed it up and then forward could feel like a gate or valve type operation like was opening and i fired heating up light and has stayed light heating working tried water and water seems ok will turn off in while and try fire it back up yo u think maybe diverter valve got stuck cheers for info so far so good