Potterton Netaheat pilot always on

[tan159753]

My retired elderly relative has an old potterton netaheat 10-16mk2 installed way back in 1981.

Everything in running tops, purring like a kitten........ until the chaps renewing the gas pipework in the street did a leak test from the meter and said there was a gas leak. They then found that the pilot light always remained on even when the main burners were off.

The vapour mercury switch thing that sits on the gas valve was changed (at a costly £180 - for a switch!!) but it did not solve the problem.

QUESTION is, in these old old boilers, is the pilot supposed to stay on anyway? Does anyone know the answer to this or is the pilot supposed to go off too when the burners go out? Otherwise it works fine but they are refusing to switch the gas back on until the PROBLEM is rectified/

 

[picasso]

The mark 2 has electronic ignition, so there should be no pilot when the main burners are off.

 

[mysteryman]

It has to be the main multifunctional gas valve if it is letting by to the pilot when electrically dead.

If it was a professional who made the incorrect diagnosis, you may have redress from him.

These were amazing boilers - just a lump of cast iron for the important part - the primary heat exchanger - with ridiculously complicated controls!

Poor thermal efficiency.

 

[tan159753]

Actually when you swich off the electrical supply, the pilot goes out. Its just in normal operation when the main burners are not on that the pilot stays on.

Could this be the relay thing on the PCB or the gas valve. The diagnosis and install of the mercury switch was by a supposedly corgi reg. What I did notice after the part was fitted that when the burners came on, I felt a small blast of air on my face when standing close to the boiler. I take it this means a leak? I have advised my uncle not to use the boiler until further notice

 

[mysteryman]

You have a case leak.

As far as I remember, the pilot should not remain alight when the main burner is not on - it is not a permanent pilot. Therefore, there is an electrical fault of some sort if the pilot goes out when you turn off the electricity. Possibly the pcb.

You must get a competent professional in.