[Bordo11]

Radiant heating system, old installation, using baseboards, using Peerless MI series boiler.
Want to ask for advice, would this idea work:
To increase safety level in case the main gas valve will get stuck open (this can happen) to install an additional solenoid, normally closed gas valve. For example Honeywell V8295A1016:
https://www.supplyhouse.com/Honeywe...ell-V8295A1016-1-2-NPT-Pipe-Size-Solenoid-Normally-Closed-Gas-Valve-2-psi-rated

That gas valve can be installed inside the boiler case, wired to an auxiliary 24VAC transformer (can be installed out or inside) through a few additionally installed rollout thermo switches or even a thermo switch with 250F trip point on the boiler supply side pipe.
In case the main gas valve gets stuck, temperature starts raising, the aux valve will cut the gas.

Is this an acceptable installation/modification?

 

[Bordo11]

The one scenario that can happen is the old pressure regulator outside the house, fails, gives much higher than 1/2PSIG to the house, might damage the heating appliance valve.
I read that back in 2018 in Massachusetts were few house fire cases caused by the increased gas pressure from the gas distribution company.
Too high pressure can get valve stuck open.

The question is, is an aux gas valve installation can be done without violating anything?

 

[Bordo11]

@Pecmsg, thanks for your comment.
How about the National Fuel Gas Code, would they be OK if the appliance gas piping is not installed according to equipment manufacturer?

 

[Bordo11]

Thanks to all for your comments. I will think of installing a combi gas valve. Need to keep customer satisfied.

I guess that gas valve failure worry might be coming, hypothetically, from thinking what happens if a piece of debris particle from the gas pipe gets inside the valve and gets the moving part (that closes the gas path) stuck? Or overtime a large amount of debris deposits inside the valve will be collected blocking the actuation process.