Hello,
Have a 30 year old forced Hot Water System (Gas fired);
2 zones-an upstairs and downstairs. Typical Colonial. Live outside of Boston.The system works as a "Millivolt" system.
Just great, as when we lose power, you can still run it as a gravity system. It will just cycle between he high and low furnace settings if the switch on it is set to Manual.
Normal thermostat, of course, would not be functional in power outage.
No Circulators, but quite enough to keep house reasonably warm. Terrific, and great to have.
Question:
a. I heard these Millivolt systems are illegal now ? Is this true ?
May want to replace heating system, as it is about 30 years old now.
b. And, what is the purpose of the one-way flow valve that is in each leg of the piping going to the Circulators ?
To run as a Gravity System, you have to disable these valves (open them up) Takes about 20 turns !
What, exactly do they do ?
What are the negatives, if I always leave them open ?
One doesn't work too well anymore. Suggested brand and model number for a replacement, if you feel that they are truly necessary ?
Thanks for thoughts on, Bob