I'll know shortly if my gas valve/operator is the cause of my boiler not firing
up. It's on an old Baxi Bermuda 551. The boiler pilot light is lit.

Q1: If the valve's ok, and it's just the operator that's died, can I replace it
without disturbing the gas path? (Put another way, does removing the operator
let the gas out?)

Q2: How to set the adjuster after remove/replace?

I did a quick Ohms test on the thermostat:
Off = open circuit.
On = about 1 Ohm (regardless of setting).

I'll check if power's getting to the valve.

Thanks

Edwin
Bath.

On Wed, 11 May 2005 16:25:52 +0100, Edwin Spector wrote:

I'll know shortly if my gas valve/operator is the cause of my boiler not firing
up. It's on an old Baxi Bermuda 551. The boiler pilot light is lit.

Q1: If the valve's ok, and it's just the operator that's died, can I replace it
without disturbing the gas path? (Put another way, does removing the operator
let the gas out?)

Q2: How to set the adjuster after remove/replace?

I did a quick Ohms test on the thermostat:
Off = open circuit.
On = about 1 Ohm (regardless of setting).

I'll check if power's getting to the valve.

The valve used is a multifunction unit.
It comprise the thermocouple valve, pilot supply, solenoid valve and
gas pressure regulator. The operating solenoid is integral with the whole
valve.

After the main valve (likely £50-100) is replaced you would adjust the
pilot flame and set the burner pressure to that indicated on the rating
plate then confirm that the gas rate is 90-105% of the intended rate.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

In message , Edwin Spector
writes
I'll know shortly if my gas valve/operator is the cause of my boiler
not firing up. It's on an old Baxi Bermuda 551. The boiler pilot light
is lit.

Q1: If the valve's ok, and it's just the operator that's died, can I
replace it without disturbing the gas path? (Put another way, does
removing the operator let the gas out?)

Q2: How to set the adjuster after remove/replace?

I did a quick Ohms test on the thermostat:
Off = open circuit.
On = about 1 Ohm (regardless of setting).

I'll check if power's getting to the valve.

Best first to check that the solenoid isn't open circuit

--
geoff

raden wrote:
....
Best first to check that the solenoid isn't open circuit


The solenoid is indeed open circuit. When it's switched on, it has 240V across
it, but nothing happens.

I learned that Honeywell do replacement operators (solenoids) for their valves.
Details at
http://content.honeywell.com/uk/home...s%20Spares.pdf

I expected that to be a cheaper solution than replacing the entire valve
assembly, and a lot easier.

Ed Sirett wrote:
....
The valve used is a multifunction unit.
It comprise the thermocouple valve, pilot supply, solenoid valve and
gas pressure regulator. The operating solenoid is integral with the whole
valve.

After the main valve (likely £50-100) is replaced you would adjust the
pilot flame and set the burner pressure to that indicated on the rating
plate then confirm that the gas rate is 90-105% of the intended rate.

Thanks for that. How is gas rate measured? Also, how is the pilot adjusted?

Regards

Edwin.

On Thu, 12 May 2005 09:20:07 +0100, Edwin Spector wrote:

raden wrote:
...
Best first to check that the solenoid isn't open circuit


The solenoid is indeed open circuit. When it's switched on, it has 240V across
it, but nothing happens.

I learned that Honeywell do replacement operators (solenoids) for their valves.
Details at
http://content.honeywell.com/uk/home...s%20Spares.pdf

I expected that to be a cheaper solution than replacing the entire valve
assembly, and a lot easier.

Ed Sirett wrote:
...
The valve used is a multifunction unit.
It comprise the thermocouple valve, pilot supply, solenoid valve and
gas pressure regulator. The operating solenoid is integral with the whole
valve.

After the main valve (likely £50-100) is replaced you would adjust the
pilot flame and set the burner pressure to that indicated on the rating
plate then confirm that the gas rate is 90-105% of the intended rate.

Thanks for that. How is gas rate measured? Also, how is the pilot adjusted?

Some but not all solenoids can be exchanged.
Gas rate is maeasured as detailed in the gas fitting FAQ
The pilot is adjusted be the pilot adjusting screw on the multifunction
valve.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"Ed Sirett" wrote in message
news
On Thu, 12 May 2005 09:20:07 +0100, Edwin Spector wrote:

raden wrote:
...
Best first to check that the solenoid isn't open circuit


The solenoid is indeed open circuit. When it's switched on, it has 240V
across
it, but nothing happens.

I learned that Honeywell do replacement operators (solenoids) for their
valves.
Details at
http://content.honeywell.com/uk/home...s%20Spares.pdf

I expected that to be a cheaper solution than replacing the entire valve
assembly, and a lot easier.

Ed Sirett wrote:
...
The valve used is a multifunction unit.
It comprise the thermocouple valve, pilot supply, solenoid valve and
gas pressure regulator. The operating solenoid is integral with the
whole
valve.

After the main valve (likely £50-100) is replaced you would adjust the
pilot flame and set the burner pressure to that indicated on the rating
plate then confirm that the gas rate is 90-105% of the intended rate.

Thanks for that. How is gas rate measured? Also, how is the pilot
adjusted?

Some but not all solenoids can be exchanged.
Gas rate is maeasured as detailed in the gas fitting FAQ
The pilot is adjusted be the pilot adjusting screw on the multifunction
valve.


Honeywell may list the operator as a spare but you might find actually
getting hold of one is an entirely different kettle of fish. Not many
suppliers will be prepared to order a single item with (probably) a high
minimum order charge. Swapping the valve might be cheaper and quicker

Ed Sirett wrote:
....

Some but not all solenoids can be exchanged.
Gas rate is maeasured as detailed in the gas fitting FAQ
The pilot is adjusted be the pilot adjusting screw on the multifunction
valve.



John, Ed, Geoff,

thanks for the helpful advice. I did find the solenoid advertised separately,
but it costs more expensive than the complete assembly. Best price was £34 from
keeptheheaton.com (.)

I may try swapping the solenoids first, so as not to disturb the gas integrity.
(You can probably tell I'm an elec eng).

Ed, particular thanks for the Gas Fitting FAQ - lots of useful stuff there.

Now I just need to find the rating of the boiler, to set the correct
pressure/flow rate. I'm not sure if it's visible on the (back) boiler. I didn't
get a manual when I bought the house.

Edwin.
------

"Edwin Spector" wrote in message
...
Ed Sirett wrote:
...

Some but not all solenoids can be exchanged. Gas rate is maeasured as
detailed in the gas fitting FAQ The pilot is adjusted be the pilot
adjusting screw on the multifunction
valve.


John, Ed, Geoff,

thanks for the helpful advice. I did find the solenoid advertised
separately, but it costs more expensive than the complete assembly. Best
price was £34 from keeptheheaton.com (.)

I may try swapping the solenoids first, so as not to disturb the gas
integrity. (You can probably tell I'm an elec eng).

Ed, particular thanks for the Gas Fitting FAQ - lots of useful stuff
there.

Now I just need to find the rating of the boiler, to set the correct
pressure/flow rate. I'm not sure if it's visible on the (back) boiler. I
didn't get a manual when I bought the house.

There should be a plate with the boiler details on the appliance. IIRC Baxi
have this on the front of the combustion chamber
Since you are going to need a manometer to set the gas pressure it would be
helpful to measure it "before" swapping the gas valve. This will form a good
basis for the setting after. I realise in your case there isn't the
opportunity if the valve is not opening:-(
I think you will find that swapping the actuator solenoind may disturb the
gas seals anyway so I'd suggest you buy the complete valve. Also but a small
tin of Rocol Gas seal and use it (sparingly) on the joints/threads