Oil fed worcester-bosch 12/15 Danesmoor boiler, which has stopped heating water

[Burnerman]

Obviously the immersion heater is ok so we can ignore that, but you need to check the fuse in the spur box marked 'central heating'.
This one supplies power to the heating programmer on the wall and if you can't get any lamps to come on there ( and the spur fuse is good) then I would guess the fault is within this, rather than the boiler unit.
Once the programmer plays ball, the top lamp on the boiler will glow red and then we're in business!
John

 

[Burnerman]

I've just looked at the programmer screen, and you see those two black LCD rectangles? They are both showing off. Use the select buttons to move them down to on once, on twice or whatever.
Damn these tiny screens!
John

 

[GJUK]

Hi.

The programmer has power, the LCD is displaying the the time and even if you switch it to 'on' (a red light comes on, on the programmer only) the boiler does nothing.

Only when the programmer is on, and the boiler is set to C/H does the pump in the boiler start to whirrr.

IF the feed to the programmer is the same to that of the boiler (looks daisy chained with no extra fuses) the problem must be an internal boiler fuse?

 

[Burnerman]

Well, it sure looks that way......presumably nothing happens when you switch to hot water either?
At this point I think I'd be checking if the boiler is receiving 250v from the programmer but I can't remember if the boiler light is controlled by the fuse on the circuit board or not - sorry!
Obviously we now know the programmer is doing something, but we don't know if it's providing an output!
John

 

[GJUK]

If you switch the hot water on, you get nothing. if you switch the c/h on you hear the pump but no heat.

I've had a look at the circuit board but can't see any obvious fuses.

programmer is working enough to tell the boiler when to be on/off. the c/h pump is certainly working when told to work.

 

[oilhead]

The overheat thermostat has tripped. The reset button is either on the underside of the panel, to the left of the lights, or on the back of that same panel. Switch on so that the pump is running, and press the red cross button. The boiler should start.

 

[GJUK]

I cant see anything under the two read LEDS or anywhere else, which panel are you referring to please?

 

[GJUK]

That worked!!!!!!!!!!!

yay, thank you very much oilhead and burnerman!!!

Jon

 

[oilhead]

As you have a sealed system, always make sure you keep a pressure of around 1 bar on the gauge. If it falls towards zero, you lose the head to the pump and it cannot circulate the water. The boiler then overheats and cuts out the burner.

 

[GJUK]

Thank you very much for the advice.
Top guys Cheers chaps, owe you a beer!

 

[GJUK]

Hi guys,

I am back!

The boiler has locked itself out again after about a weeks use, the water pressure is 1.2 bar, is this normal? The pressure is above the red marker so I assume it is a little high.

How do I drain pressure off please?

thanks

Jon!

 

[Burnerman]

That sort of pressure should be fine, but if you want to reduce it, bleed water out of any convenient radiator.
Is the pump speed set on 3?
John

 

[GJUK]

It is set to 2. I think there is a I II and III setting. it is on II.

Cheers

 

[GJUK]

Hi guys,

Any further ideas on this please? Something must be tripping it and the reset button no longer 'resets' the boiler. It has the light 'lock out' shown now along with the power light.

 

[Burnerman]

Unfortunately we have another issue here......the lockout light means the oil burner itself has had some sort of failure, in other words it hasn't been able to light up or remain burning.
This isn't anything to do with the boiler overheating!
Press the illuminated lamp on the burner itself, and let's see what happens.
Ideally the burner motor should start, which purges fresh air up the flue. After a few seconds, the oil is then electrically switched on and it should light up.
Stand by to report back when you try!
John