Possible heat pump issue...

[K Frame]

OK, hopefully one of our HVAC guys here will have some ideas.

I turned my heat on this morning after the house got down to 63.

House temp 65 at the thermo, so I turned it to 68.

As expected, the heat pump and the auxiliary heat came on. That happens when the temperature differential between the house temp and the asked for temp is more than 1.5 degrees.

Only... when the house temp hit the asked for temp, the auxiliary heat didn't turn off, nor did the system, so it overran the thermostat.

It did that twice for me.

So, I shut the heat off, took the unit off the wall, give it a through dusting out, and changed the batteries.

Since then I've not had a call for heat, so I don't know what's going to happen.

Any thoughts?

Potential for a bad thermostat? It's close to 30 years old, it's a Honeywell Climatron III programmable.

[bedlamite]

[K Frame]

It seems to have calmed down and is working correctly now, I think.

Still going to schedule a service. It's been a couple of years. And, it's probably time to get a new thermostat. That one is nearly 30 years old, and that's quite old for an electronic thermostat.

[JTHunter]

It seems to have calmed down and is working correctly now, I think.

Still going to schedule a service. It's been a couple of years. And, it's probably time to get a new thermostat. That one is nearly 30 years old, and that's quite old for an electronic thermostat.

Is it a digital and/or programmable thermostat?  I'm asking as I have a "5 + 2" programmable that we installed in this house over 18 years ago.  We replaced the old "dome" (Honeywell?) thermostat with this one.  I just keep changing the 2 AA batteries every so often.  There are a pair of lithium batteries in there now and I think they have been in for 2-3 years.

[Brad Johnson]

The stat's display temp was reading the overrun?

Brad

[K Frame]

I finally found the paperwork on it.

It's a Honeywell Chronotherm III from 1995.

It's a fully programmable unit.

I've never used the programming because I found that it was far more effective, cost efficient, and overall comfortable to simply set the heat in the winter and select Hold Temp and not change it.

In the summer I manually lower the AC level when I get home from work and then turn it back up when I leave for the day. That's primarily to ensure some level of adequate dehumidification since the system is now quite oversized with all of the energy improvements I've done over the past few years.


And yes, the display temp was reading the overrun by several degrees before it would finally shut down.

But, as I said, it seems to have finally settled down since I removed it, very thoroughly air dusted it, and put in a fresh set of batteries.

We'll find out, though, as it's supposed to get quite chilly the next couple of days. 

[JTHunter]

I finally found the paperwork on it.

It's a Honeywell Chronotherm III from 1995.

It's a fully programmable unit.

I've never used the programming because I found that it was far more effective, cost efficient, and overall comfortable to simply set the heat in the winter and select Hold Temp and not change it.

In the summer I manually lower the AC level when I get home from work and then turn it back up when I leave for the day. That's primarily to ensure some level of adequate dehumidification since the system is now quite oversized with all of the energy improvements I've done over the past few years.


And yes, the display temp was reading the overrun by several degrees before it would finally shut down.

But, as I said, it seems to have finally settled down since I removed it, very thoroughly air dusted it, and put in a fresh set of batteries.

We'll find out, though, as it's supposed to get quite chilly the next couple of days.

Good luck !

[RocketMan]

Good luck !

We're all counting on you.

[K Frame]

Sometime in the next couple of weeks I'm going to make an appointment for a company to come in and service it (it's been a few years) and I'll probably have the thermostat replaced at the same time for something a bit simpler but maybe also wifi enabled so that I had adjust it with an app on my phone.

Not Alexa, Dot, or Echo, just straight up wifi.

[JTHunter]

Not Alexa, Dot, or Echo, just straight up wifi.

Have you ever heard the term "war-driving"?  Wifi means that your power company might be able to alter your settings too.

[K Frame]

Yeah, they keep trying to get me to sign up for smart monitoring smart use programs all the time. I've always demured because my usage is quite a bit under normal for a house this size.