Boiler problems. Pilot Light

[AndyBa]

Hi there,

I have an old combi boiler that switches off when I turn the hot water off. It isn't connected to any central heating system. I just heats the water to the taps. After I have turned off the hot water and the boiler clicks off, if I turn the hot water tap on again the tap blows out piping hot water and steam. Sometimes there is a clicking and banging noise from somewhere. Either the boiler or the pipes.

Can you help me to diagnose the problem at all?

Thanks,

Andy.

 

[namsag]

Gas is staying on and still heating the water. What combi is it

 

[mickyg]

I'm guessing its a water heater. One of them nice ones that catch fire when the plunger gets stuck and leaves the burner on..........

Gas is staying on and still heating the water

wait a minute...

 

[namsag]

My thoughts exactly mickey.

 

[AndyBa]

It is definately switching off. The pilot light goes out but when I turn the hot water tap on again it blows out steam and boiling hot water for a few seconds before it goes cold and sometimes there is a banging noise from the pipes or the boiler.

It is a manufactured by Main and is called a Main Mersey.

 

[namsag]

As we thought you dont have a combi you have a multipoint water heater.

It is not turning off straight away when you turn tap off it has a sticking pushrod and gas is staying on longer than it should before tripping overheat stat and pilot overheat.

Can be very dangerous stop using it and get someone out straight away straight forward repair

 

[Agile]

If the waterway has got scaled up then the fins will get hotter than normal and retain latent heat which transfers into the water and cause that to boil.

Thats the likely cause if the gas really does go out immediately a tap is turned off.

Tony

 

[powell30]

Repaired one the other week with exactly this problem......push rod gunged up leaving the boiler thinking it had flow.......switched off slowly so water continued to heat. I would suggest OP gets a repair on the flow switch and gets a new heat ex.....comes as one unit (heat ex that is).....not a DIY job i'm afraid

 

[namsag]

Why would he need a new heat exchanger

 

[Agile]

It is definately switching off.

It is a manufactured by Main and is called a Main Mersey.

He seems sure that it is turning off immediately the tap is turned off.

Even if it was the pushrod sticking then thats not a DIY job either as its a gas control with safety implications.

Tony

 

[namsag]

Who said it was a diy job .