Troubleshooting: blower is on, circulator is off
Hello all, I’m new to the forum and have a question that someone might be able to help me answer. And I’m not an expert in this arena, so I might not get the terminology right here. I have a 2 zone HVAC system. Identical thermostats made by RiteTemp that I got at HD a year ago. When I turn on the heat for the 2nd floor, the blower fires up, valve opens at the boiler, circulating pump turns on, and the boiler fires up if the water is cool. (I have one blower in the attic, and one in the basement – it’s an old house and was installed well before I moved in a year ago) I came home a few weeks ago, I found that the blower was on for the first floor, the valve was open, and the pump was off. The water was cool. I messed around with it for a bit, found that the air vent above the expansion tank was leaking, and replaced it. But that clearly wasn’t the issue. I turned the boiler on and off at the shutoff switch a few times, and eventually it clicked on. I decided to replace the batteries in the thermostat and found that once I did that, all operated normally. I turn on the heat, I hear a click, and I can hear the pump start up. If the water is cool, the boiler fires up. What I’m confused about is why the thermostat would be sucking batteries dry so quickly. I replaced the batteries at the beginning of the winter. Then did it again last week. And needed to do it again this morning. Could I have a bad thermostat? Do they go bad? Appreciate any guidance/advice/spells you might suggest.
Replies
Well ... your description of your system is a little vague. If I take your description literally, it sounds like you might have a boiler to a hot water coil located in ductwork (as opposed to a strictly furnace/forced air system or a strictly hydronic system). Direct-vent (mod con) boilers do have internal blowers but they aren't such an obvious part of a heating system (as in a forced air fan).
Do you have a system like this (unusual but they do exist) or is it really either forced air (registers) OR hydronic (baseboard heat/radiant/radiators etc.)?
In either case, most thermostats take power from a transformer in the heating system with batteries as a backup ONLY (so they don't lose their settings during a power outage). RiteTemp refers to this as 'an optional C wire.' It sounds as if the low-voltage power (C wire) to the thermostat might not be connected - check the wiring diagram for your stat and see if you have power (probably 24V) to the power legs of the stat. Also, if you take the batteries out and it doesn't work it is likely that the C wire isn't connected. You can have someone install this.
See this link - http://www.ritetemp-thermostats.com/faq_operation091018.pdf
If you don't have low-voltage power to the stat it will run on batteries only - but it will exhaust them. You might want to change to lithium batteries (do not use rechargeable batteries).
You can troubleshoot more here - http://www.ritetemp-thermostats.com/faq_trouble091018.pdf
Jeff - awesome answer.
But why "don't use rechargeable?
But why "don't use
But why "don't use rechargeable?
Because the manufacturer SAYS not to.
Jeff-
First of all, thanks for this.
I wasn't that great in describing what my system. It's a forced air unit. I have one heat exchanger and blower in the basement, and another setup in the attic.
I don't have a C wire. There is a blue wire, but it was cut at the wall and unattached to the system when I moved into the house 2 yrs ago.
I went ahead and replaced the thermostat today. I woke up yesterday and found the blower running, but cold water in the pipes and no action at the furnace. It was 60 in the room, the thermostat was set to be 66, and just to mess with it I turned it up. I didn't get a 'click" till I hit 77. So replacing it seemed like a good start - the thermostat upstairs doesn't do that - same model & make, and installed the same day.
I also noticed that the zone valve for the first floor is warm and was making noises when I turned the system on. I popped off the cover, and sure enough it looks like it might have been sticking or not fully opening. Now I'm noticing that when I turn on the heat, the sequence is:
-blower engages
-zone valve opens, and the second it's fully open
-circulator pump engages
-if needed, furnace fires up
I'm guessing that a warm/hot zone valve or one that makes a noise I'd notice is one that probably needs replacing, no?
And again - thanks for answer. I know I'm not describing this well at all.
Long shot: If they are digital thermostats, are you selecting/programming in the correct type of heating system for anticipater function?
Please clarify exactly what heats your water.