Combination gas valve.

[mike2525]

Can you test a removed combination gas valve, the standing pilot type, by wiring it up to a plug top with a 3amp fuse to see if the solenoid will energise?

 

[GasManMikey]

Multimeter, ohms setting. Check on gas valve pins/terminals and/or check solenoid

 

[DP]

Can you test a removed combination gas valve, the standing pilot type, by wiring it up to a plug top with a 3amp fuse to see if the solenoid will energise?

What is that going to achieve?
Solenoid operation does not mean gas valve will work, only that the armature on the operator has moved to open position.
What use to be individual components on the gas train are now housed within single package, any of these could cause the valve to malfunction.

 

[mike2525]

Multimeter, ohms setting. Check on gas valve pins/terminals and/or check solenoid

On 2k ohms setting, I don’t pick up a reading. On 200k ohms the resistance is fluctuating everywhere between 5 and 60. What sort of Reading would you expect?

What is that going to achieve?
Solenoid operation does not mean gas valve will work, only that the armature on the operator has moved to open position.
What use to be individual components on the gas train are now housed within single package, any of these could cause the valve to malfunction.

I understand that, it’ll possibly rule out a defective solenoid coil or confirm the valve is faulty?

 

[Gasguru]

What are you trying to achieve?...diy gas on the site is not permitted and the post will be locked...
If you're an rgi join the CC where this can be discussed.

 

[durhamplumber]

Multimeter, ohms setting. Check on gas valve pins/terminals and/or check solenoid

Not with mains on!!

 

[mike2525]

What are you trying to achieve?...diy gas on the site is not permitted and the post will be locked...
If you're an rgi join the CC where this can be discussed.

I’m currently training to become an rgi. College is closed due to the current pandemic. I’ve been trying to learn about older components in more depth! But I can’t find anything about testing for a compromised solenoid. To clarify, there’s no gas involved. By all means close up the thread if it’s against rules tho.

Not with mains on!!

Ofcourse!!!

 

[Gasguru]

99% of faults on solenoids are due to the coil becoming open circuit so a simple resistance reading is all that's required.

The main safety valve solenoids (often marked as EV1 or EV2) are normally operated at either...

240 Vac
240 Vrac (that's unsmoothed rectifed AC so around 200 odd volts dc but it depends on your multimeters interpretation of the rough waveform - there are some benefits over pure ac)
24 Vdc
24 Vdc (but switching down to 12 Vdc after a second-many modern boilers are now like this for energy saving).

The higher voltage coils are typically a few Kohms and the lower voltage coils typically around a 100 ohms.

Be aware that there are some old gas valves eg. the Potterton Profile White Rodgers valve that have a few extra components in the connector block to enable the valve to be fed with 240 Vac but the coil operates on 240 rac so you'll get odd readings. Most gas valves operating on 240 Vrac have either a special harness incorporating conversion components within the molded connector or they are part of the main boiler circuit board.