Potterton Netaheat 10-16 not working

[Pants]

Although I'm not gonna touch it, its still buggin me whats up with the mercury valve whether on cold it should be open or closed?
I know the Netaheat is old but its been very reliable,
If I get a new boiler what would you recommend for a conventional fully pumped sytem?

 

[Agile]

Sorry Chris, you are right, the 35 sec was the one I was looking at! Yours is even more aged!

Its probably all correct Mike except for the penultimate paragraph!

The Hg switch is on a 4 pin ( B4 style ! ) connector on the end of the gas valve and it would be easy to assume that it was a mechanical opening of the main gas valve.

The Hg SW is powered via the gas valve and it powers the main solenoid via this series resistor when the sensor is hot.

I would be very surprised if the stat only turned off the fan and relied on the APS to shut down the gas. I expect it kills power to the gas valve as well.

Tony

 

[ChrisR]

On the new one, looking at the pins with the resistor at the bottom they're numbered

[code:1] 3

2 4

1
[resistor][/code:1]

And (only) pins 1 and 4 are connected, at room temp.

 

[Pants]

Have had an engineer look at the boiler - he says it is definetely the MV - only problem is cannot seem to get hold of one anywhere, they where made obsolete as from Dec05.
Some websites still have them on their parts list, but none seem to have any in stock.
Anyone out their got a spare one lying around?

 

[Agile]

We have both a new one and a used one in stock! We like to keep spares in stock so we can fix what BG fails to fix!

However, you first said that the boiler does fire up. That means to me that the problem is NOT the mercury switch!

I do not supply spare parts to anyone unless I am convinced they need them!

Tony

 

[Pants]

For me the boiler was now totally dead, but when the engineeer came in, after testing a few components he then turned on all the heating controls including roomstat - the boiler was still dead, until he tapped the MV switch (with the two yellow wires) with a screwdriver handle.
(The switch has a note saying 'Do Not Open').
The pilot light then fired up and after a few seconds the boiler was workin.
But once the call for heat is removed the boiler switches off and will only come on again when the switch is given another tap.
He says the switch is sticking and will need a new one.
But he's not got any, and can't get one?
Please advise
Regards
Graham

 

[ChrisR]

Hang on, we - or I anyway, have been confusing things here. The MV switch on the Mk1 is NOT the same as the one on the Mk2, which I and others have been talking about. Sorry.
Looks like a switch from a ripped-out boiler may be your only hope.

 

[jonah57]

Sorry to butt in on this debate but I couldn't work out how to send this question out there to everyone any other way?
I have a problem (via my plumber friend) with the vapour valve switch on my very old potterton netaheat 10-16 boiler. Although it still just about works at a very low gas pressure with very lukewarm temperatures to the radiators, the plumber has isolated the problem (by a process of elimination) to be the vapour valve switch not working properly! We cant find a replacement in this area due to the age of the boiler and even if we could, a price of £200ish for a new one is not worth paying on a boiler on its last legs! I will be gutting my kitchen in a couple of years (cant afford it now) so I would prefer to keep it going a bit longer if I can?
Does anyone know where I can get a cheap or secondhand replacement valve to keep it going or even have an old one lying around that we could work out a price for?
Cheers
Graham

 

[Pants]

Hi, I believe the mercury vapour valve for the 10-16 is now obsolete,
I tried various outlets to see if they still had one in stock
- couldnt get one anywhere.
However, I got lucky and found a nearly new one on ebay for less than £40 which I had fitted by a corgi friend,
Although the boiler is around 33 year old it is still working fine
Good luck!