What temperature do you leave your home at

[RobWNY]

Today, I had my furnace guy come for the annual check-up, cleaning etc. I've known the guy for many years. I was telling him that next year we would be spending winter in the South and was planning on setting my furnace thermostat at 50 Degrees. He advised me not to do that. He said 60 Degrees minimum for my high efficiency furnace. He said moisture will accumulate in the heat exchanger if the furnace doesn't cycle enough and get hot enough. The life of the furnace will be reduced. I had never heard of that before. He said to think about it like a car exhaust. If all you do is drive it to the store and back, the exhaust never gets hot enough to evaporate the moisture and it rusts prematurely. He said the same thing happens with these high efficiency furnaces. So what do you think? What type of heating system do you have and what temperature do you leave your thermostat set to when away?

[Geeze]

We have a Simplisafe security system. I have one of those large round outdoor thermometers in the house where one of my security cameras can see it. I can remote in and check the tempreture in the house.

[Sam_Spade]

joebedford wrote:

Michelle.S wrote:
several gallons in the toilet tank and bowl

Why so much and why in the tank?

Why NOT in the tank ?

It's a lot easier to do that than it is to try and mop up ALL of the water that is in there.

If you flush out most of the water, it really won't take much.

[joebedford]

Michelle.S wrote:
several gallons in the toilet tank and bowl

Why so much and why in the tank?

[steveh27]

When I leave for 7 weeks in MI, I set the older furnace (not high efficiency) at 52. I leave the water on for the furnace humidifier and my neighbor who gets my mail daily, and waters my plants every week or so.

[Michelle_S]

OK, a previous poster was looking for it so here it is:
We don't winterize our RV, we winterize the House if Western NY (Rochester/Buffalo area). Drain the Hot Water heater, Hookup the air compressor and blow all the water lines out, put RV Antifreeze (Yea the pink stuff) in all P or S traps, several gallons in the toilet tank and bowl, approx a gal in the washer and run on drain to ensure pink stuff in it's pump, open most of the windows just a crack to help equalize inside and outside temps, contact the power company and shut everything off.
Been doing this now for a number of years without an issue.

[Sam_Spade]

pasusan wrote:
Thank you Carrier for replacing them when they rusted out. We're just waiting for them to rust out again...

I suspect that was just a screw up on their part.
I also suspect that the replacement will out live YOU.

Carrier doesn't sell junk.....at least not on purpose and not with their name on it.

[pasusan]

Sam Spade wrote:

almcc wrote:
it gets the high efficiency by condensing the water out of the flue gas, comments about rusting in these furnaces are incorrect (bogus).

Close but not quite.

It gets the high efficiency by capturing most of the heat from the flue gasses with a more elaborate heat exchanger. A side effect of that is condensing out more moisture.

But you are essentially right.....about the combustion components which are stainless steel and won't rust.

The entire unit, however, is NOT rust proof and if the general environment gets really moist, so will the cabinet and other components outside of the combustion path. Hopefully none of them would rust to the point of failure though.

Huh? We have a high efficiency gas furnace and the heat exchangers are definitely not stainless. Thank you Carrier for replacing them when they rusted out. We're just waiting for them to rust out again... And we've never left the house for any long periods in the winter.

[babock]

Thunder Mountain wrote:
We leave ours on 55 degrees. I use a program called TeamViewer running on an old XP computer on our home network and remotely monitor a Davis Weather Pro weather station that gives me inside and outside weather data. I also have a Logitec webcam looking out the window. I check them every morning and have a neighbor on call if there is a problem.

Why not use an internet connected thermostat? It will send you text messages if the temp falls below a certain temp. I use one in my vacation home in Lake Tahoe. They are very inexpensive.

[Edd505]

We leave it at 55 but didn't turn the water off. Got a call from the water co. they had shut it off as we had an $800 water bill. When I got back home I found a float in one of the toilets had sunk.

[jplante4]

RobWNY wrote:
For what it's worth, here's a link to a discussion on this topic from HVAC-TALK in 2014.

clicky

[Sam_Spade]

almcc wrote:
it gets the high efficiency by condensing the water out of the flue gas, comments about rusting in these furnaces are incorrect (bogus).

Close but not quite.

It gets the high efficiency by capturing most of the heat from the flue gasses with a more elaborate heat exchanger. A side effect of that is condensing out more moisture.

But you are essentially right.....about the combustion components which are stainless steel and won't rust.

The entire unit, however, is NOT rust proof and if the general environment gets really moist, so will the cabinet and other components outside of the combustion path. Hopefully none of them would rust to the point of failure though.

[RobWNY]

For what it's worth, here's a link to a discussion on this topic from HVAC-TALK in 2014. https://hvac-talk.com/vbb/showthread.php?1675591-Setting-thermostat-too-low-will-damage-gas-furnace-heat-exchanger

[joebedford]

I checked with my furnace tech and read the manuals that came with my furnace and there was no mention of a minimum set point because of the risk of rust. I'll stick with 8C.

[almcc]

Just a couple of thoughts from a retired "tekkie". The temp you want to set the house at depends on the humidity over the winter period in your area. For us, it's so dry that I have to tighten up the cupboard door latches in the spring when we return home. You may want to research the highest sustained dewpoint in your area and consider setting the temp above that to prevent mould, if you live in a wet area.

We set our furnace at 10.5C, that's around 52F. After doing heat loss calcs for Y2K, I'm comfortable with the temp, it would take a long time (a day or more) for the temp to reach freezing. In addition, I turn off the water and most of the water pipes are in our basement which I monitor and it stays at a higher temp than 10.5. I have remote temp monitoring and control with email warnings to me and our house checker if the temp drops below 8.5C.

A final comment, we have a high efficiency gas furnace, it gets the high efficiency by condensing the water out of the flue gas, comments about rusting in these furnaces are incorrect (bogus).

[Sam_Spade]

pawatt wrote:
I am surprised we have not heard from anyone who drains the water and just turns the heat totally off. This is what many in northern Minnesota do.

Depending on your specific plumbing, that can be a GIANT pain in the backside.

Of course, once you know the importance of leaving faucets open, it becomes less of a pain.

My parents did that with their old farm house every winter for about 10 years. They were in Illinois. The problem with that IS.....that if the temperature fluctuates enough, there will be a moisture buildup inside which can cause a REAL mess if mold starts.

In northern Minnesota it might be consistently cold enough/dry enough for that to not be a problem.

If your building feels really dank and moist when you first open it up in the spring, you might want to reconsider your plan.