I have a 2 year old Natural Gas fireplace, Mendota DXV 60, which uses a gas valve: SIT-820 NOVA mV, model 0820708.
In the last year the gas valve has failed 4 times. I have had it replaced, 4 times, by a Mendota authorized service provider. Neither the repairman nor Mendota can determine what the problem is. I'm told these valves should be trouble free for many years.
National Grid, gas provider, has investigated the gas supply and has not found any issues.
the fireplace will be working fine and then I turn the main switch to the off position before going to bed. The next day, I turn the switch to the on position, no flame.
The pilot is still on, I turn the switch off, wait 5 minutes, turn the switch on, but no flame.
The repairman has done a series of tests and verified the millivolt readings and they're ok, except there is still no main flame.
He replaces the valve and the issue is resolved.
What conditions can cause this valve to fail?
The valve had to be replaced 4 times, this is costly.
I have other gas appliances: dryer, stove and 2 other fireplaces (different manufacturer), that do not have this problem.
I cannot afford to keep replacing the valve. Can you provide some assistance to help resolve this issue?