I have ceiling cable heat and want to replace the manual thermostats with programmable ones.

I want to replace a Singer Model 7165B, which has the following information on it:

18 Amp 277 VAC
22 Amp 125, 250 VAC
Double Line Break

I took one of the thermostats off the wall and it appears to have 4 wires connected to it, so I'm assuming I need a double pole programmable thermostat?

I've searched online but haven't found anything that can handle the Amps listed above

Any ideas on a programmable thermostat that would work with this setup?

Search this site.

http://www.white-rodgers.com/wrdhom/...hermostats.pdf

And here

Catalog

If all else fails you could use a relay to absorb the over current.

Hey, guys. I think someone is barking up the wrong tree. Don't look at the label of the stat, but the label on the heater. What is the heater watts or VA and volts?

There are a few stats here: Electric Baseboard & Line Voltage | thermostats.idtenergystore.com - programmable thermostats by Honeywell, White-Rodgers, Robertshaw, LuxPRO

A contactor can easily be added to just about any line voltage stat to increase current switching ability.
Examples: C125 Online Catalog

I only mentioned relay instead of contactor because the relay is a lot quieter than a contactor. A contactor really makles some noise (bang) when pulled in.

Been there done that.

The White Rodgers thermostats listed for line voltage located at the White Rodgers link above will cover his voltage/switching/current draw/requirements.

If you need a relay for whatever reason see the ADD A Relay here

http://www.white-rodgers.com/wrdhom/...ers_relays.pdf

Or see Level temp controls are very quiet.

http://www.white-rodgers.com/wrdhom/...ns/furnace.pdf

HVAC1000, thanks for the links and your help again.

KISS, I thought about that, but it's ceiling cable and I can't get to anything else except the stat and the breaker box. All of the breakers (4) are listed at 20 Amps. And those 4 breakers have 7 stats which control separate rooms. So with my limited understanding, I assumed that the stat rating may not be what's required, but I also don't want to put in the wrong stat.

So, you only have one other choice. Your going to have to measure the current. And (4*20)/7=11.42 or 20/2=10 and upsize by 20% you get 14.3 and 12.5. That would be guesses with 2 units per breaker. That would be an educated guess.

Measuring the current would be the best way to go. The clamp method is the easiest. See Ideal 61-701 Clamp Meter, 200AMP, Ideal 701, 61-701, 61701 A resistor will work too.

If you measure the current upsize by 20%.

Lets keep it simple for Xylo133. If the thermostat has the same or higher rate you are good to go. Actually if you use a higher rated thermostat the contacts will last longer.

It is not common sense to replace your current thermostats with lower rated ones not only because of the contact life expectancy but also the price will be about the same. Lets keep it simple.

What assumptions can I make with this additional information?

I have 4 breakers, all listed at 20 Amps.

One breaker controls one thermostat in the Kitchen/DR. Thermostat is like the one listed above.

Another breaker controls one thermostat in the Living Room, and it's also like the one listed above.

One breaker controls the heat in the hall and two small bedrooms. Only the hall thermostat is like the one listed above. The other two have no markings at all. The hall is a very small area.

The last breaker controls the master bedroom, bathroom and pantry. Only the master bedroom thermostat is like the one listed above. The other two have no markings. The master bedroom is about 2/3 the size of the living room.

I was wrong earlier, I actually have eight thermostats.

I'm only concerned with replacing the bedroom stats as I'm on time of day and the other rooms get enough heat from my keystoker downstairs.

I wasn't able to find a programmable 22A line voltage stat on any of the links, which is why I'm refining my information.


Can I assume that only half of those amps are in any given bedroom, or should I just hire an electrician?

hvac1000:

It appears that the 22A ratings are hard to come by and 15A ratings are common, thus determining the current draw offers more choices of stats.

Buying a meter might be about the price of a simple service call from an electricain to say, come out and measure the current draw of the units. With an amp clamp it's a simple matter of clamping around one of the stat wires.

Using a stat with at least the rating of 1.25 * current draw would be the minimum acceptable.

The critical piece of the puzzle is what rating is needed. For that, there are, I think 3 choices at this point: 1) Purchase an amp clamp; 2) Call an HVAC dealer and 3) Call an Electrician.

The HVAC dealer might be able to suggest stats and give you an estimate of what the job will cost. He needs to know the current too.

Something like:

Hi:

I'm interested in replacing 4 of my 240 VAC DPDT Heat only line voltage stats with something programmable. I don't have access to the model or ratings of the heaters.
What would it cost for someone to come out and measure the heater current, suggest possible thermostats and give me an estimate of the cost to do the install?