Potterton Combi 80 Starts automatically

[imranakhtar]

Everytime I turn the boiler on, the green light comes on and burner starts burning automatically without any demand for heating or hot water, and then it locks out. Also few drops are dripping from DHW switch.

 

[chrishutt]

Water leak causing short on flow switch, boiler thinks DHW on and burners light? Deal with leak - probably new flow switch.

 

[imranakhtar]

Thanks for your reply, I have checked and its not short, I have put a plastic sheet below the switch so that leaked water goes out without falling on anything inside the boiler. What else can be the cause. Really appreciate your response.

 

[B.O.B DOLE]

i think its the ch flow switch drain it down and check it

 

[B.O.B DOLE]

Everytime I turn the boiler on, the green light comes on and burner starts burning automatically without any demand for heating or hot water, and then it locks out. Also few drops are dripping from DHW switch.

try this make sure nothing is calling for heat on the facia then turn it on does it still fire up if it does there is a flow switch sticking on

 

[ChrisR]

Er, there isn't a CH flow switch ??

Is there a red light on the pcb?
Is Switched Live at live, on the connection strip?

 

[imranakhtar]

Yes the red light on the board is on (but not 100%, it is giving very little light)
How do I check the connection at connection strip?

 

[ChrisR]

Yes the red light on the board is on

Thought so. I mean we all thought so. That comes on to indicate a hot tap water flow - so the switch has probably had water in it and is looking like it's closed. Pull a lead off it!
The manual is here http://www.partsarena.com/baxi/

I have checked and its not short

Since you don't know what voltage is applied and you don't know how high the resistance needs to be, you don't know what you're testing for.

How do I check the connection at connection strip?

Switched Live is one of the main boiler input connections. It's what turns the boiler on for CH. You would typically measure the volts (mains) on it with a multimeter. Not really a suspect now, but I'd check it anyway.

 

[imranakhtar]

Why the Red LED doesn't lit fully, why is it half lit and can u please tell me how does flow switch and microswitch work.Thanks

 

[gstens baxi]

The problem lies with the dhw switch witch is a sealed unit and can only be exchanged with part of the wiring harness. You will also need the pressure differentional so call baxi.