We have a 30 year old slant fin gas fired hot water furnace. As much as I like to fix things myself whenever possible, I signed us up for the gas company service contract... $12? a month since this past july. We needed it today - the pilot light wasn't staying lit. I babysat it overnight so we were warm. A tech this AM replaced thermocouple and burner assembly. On the way out, talked of the gas valve being questionable / low side of OK. (the main point of me signing up for the plan was to get the gas valve replaced at some point). Pilot went out a few hours later. Another tech came out and replaced the gas valve / showed me a screen in there that was pretty clogged. 1) the 2nd tech said burner assembly and gas valve are usually replaced together. (ie first guy should have done the valve). Would you agree? 2) We asked the first guy about replacing the furnace. He said 'you'd usually wait till there's water on the floor'. ie cracked. He mentioned how the room it's in is clean and furnace looks in good condition. What's your thoughts on waiting till there's water? My wife heard his answer but now that the 2nd guy said the 1st should have replaced the valve, she doesn't have faith in his answer. 3) the 2nd guy said 'everything's new now' - with the replaced gas valve, thermocouple and burner assembly. I know there's much more to a furnace but would you say those are the key things that could fail? We should be good for a while? What about something like the circulating pump? Do you keep a spare? replace that proactively? No way to test that, right? Ours is a taco 007-F4. water parts aren't covered with the gas company service contract. So it'd be on me to replace it. it has a date of aug 1995 : ) Still working!

We have a Gas - Forced Hot Water heating system with two zones. The thermostats are 5+2 electronic thermostat. No AC in the house. Three days back one zone stopped working. I then restarted the thermostat (switched to off and then again to heat) and it started working. This continued for a couple of times. Next, I removed the thermostat, tightened the screws where the wires connect, changed the battery and it started working perfect. But that lasted for just a day. Now it has stopped and won't start even with restart. I have switched the thermostat with the one in working zone but that did not make any difference. What should I check next ? Wondering if there is any way to check if the low voltage connections are getting power ? wondering if I should change the entire thermostat (basically the unit where the wires are connected). Edit: Earlier, the thermostat was showing Heat On (though Heat was not turning on), but now thermostat does not even show Heat On