How high can or should I run an old heating system?


  #1  
Old 12-24-22, 04:16 AM
M
Member
Thread Starter
Join Date: Jan 2006
Location: NYC
Posts: 668
Received 5 Upvotes on 5 Posts
How high can or should I run an old heating system?

Just out of curiosity guys, we have a monster sized Thatcher 110k BTU Gas heater in this 70 year old house. I normally set the thermostat at 74 and leave it like that during the winter but on super cold and especially windy days, how high should I set it so as not to put too much strain on the heating system please?
 
  #2  
Old 12-24-22, 04:31 AM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Posts: 4,960
Received 158 Upvotes on 144 Posts
Hi, setting the stat higher will just make the heater run longer to try and maintain the set point, is this a furnace or boiler, not that it makes a difference.
Geo🇺🇸🇺🇸
 
  #3  
Old 12-24-22, 04:47 AM
M
Member
Thread Starter
Join Date: Jan 2006
Location: NYC
Posts: 668
Received 5 Upvotes on 5 Posts
Hey, thanks for helping. Its a furnace but the age of the system is what has me being maybe overly cautious.

Most people I talk to says they set around 68-70 and I do 74 to compensate for this being an old house but for old houses how high might be a recommended max setting I should go to not to put too much strain on the system whenever needed please?
 
  #4  
Old 12-24-22, 05:04 AM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Posts: 4,960
Received 158 Upvotes on 144 Posts
What temperature is the house staying at with the stat set at 74*?
Geo🇺🇸🇺🇸🇺🇸
 
  #5  
Old 12-24-22, 05:08 AM
M
Member
Thread Starter
Join Date: Jan 2006
Location: NYC
Posts: 668
Received 5 Upvotes on 5 Posts
Hmnn, never considered that to be honest because whoever had designed the heating ducting system in this house did a terrible job as different rooms has different temps or I should say one room will feel colder than another. I set at 74 because at that setting, normally has a comfortable feel in most of the rooms.
 
  #6  
Old 12-24-22, 05:14 AM
R
Member
Join Date: Oct 2016
Posts: 2,137
Received 185 Upvotes on 169 Posts
HVAC equipment has a 100% duty cycle. Meaning it can run continuously and be ok.
Your not really putting an extra strain on it, its not like driving a car with the throttle wide open everywhere.
Make sure and do seasonal maintenance and have the heat exchanger checked. Thats what causes most furnaces to go to the scrap yard and also what causes most carbon monoxide poisonings.
 
mikehende voted this post useful.
  #7  
Old 12-24-22, 05:15 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,967
Received 1,769 Upvotes on 1,582 Posts
The reason we ask what the temperature is (not how it feels, but the actual number) is to find out if the system is maxed out. If you have the heat set on 74f and the furnace is running continuously and the house is 68f then turning up the thermostat higher will not have any affect.
 
mikehende voted this post useful.
  #8  
Old 12-24-22, 05:16 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,275
Received 1,104 Upvotes on 1,004 Posts
It's not really a strain just how much longer the unit has to run to try to keep that higher set point.

It could fail at any time regardless if it was set at 65 or 74.
 
mikehende, Norm201 voted this post useful.
  #9  
Old 12-24-22, 05:35 AM
M
Member
Thread Starter
Join Date: Jan 2006
Location: NYC
Posts: 668
Received 5 Upvotes on 5 Posts
ok thanks guys.

@Roughneck77
That is exactly what one boiler repair tech had said to me couple years ago when he had asked if I think the heating system is like an old car which will break down if I run it too hard?

Regarding the maintenance aspect, I had asked this of him and he had said "if it Ain;t broke don't tamper with it". I never liked hearing that tbh because what's one to do if/when it breaks and need to wait for an unspecified amount of time before someone should get here? I had considered calling an HVAC company who was charging only $80 to do a checkup.

So guess I should go from 74 to 80 now on super cold days.
 
  #10  
Old 12-24-22, 05:52 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,275
Received 1,104 Upvotes on 1,004 Posts
So guess I should go from 74 to 80 now on super cold days.
Must have the family trained pretty good, we're 68 in the winter, sometimes with the fireplace running it will get up to 70 which feels like your walking in a blast furnace, could not imagine temps that high!

You would benefit from some air sealing maintenance and also humidification to make it more comfortable not to mention saving some $.
 
  #11  
Old 12-24-22, 05:56 AM
M
Member
Thread Starter
Join Date: Jan 2006
Location: NYC
Posts: 668
Received 5 Upvotes on 5 Posts
With a well insulated house that should be accurate, unfortunately for us, different story. only way for this old house will be to gut everything and totally insulate then put in new system but lack of finance for this has us doing whatever we can to survive.
 
  #12  
Old 12-24-22, 06:00 AM
R
Member
Join Date: Oct 2016
Posts: 2,137
Received 185 Upvotes on 169 Posts
DO NOT hire one of those cheap checkup services you see on billboards and hear on the radio. They are designed to get the companies foot in the door so they can sell you all kinds of equipment and parts. They are NOT designed to actually do any maintenance on your equipment.
You need a trustworthy company, preferably a small company with low overhead, to come in and do a full checkout. Its mandatory to check the heat exchanger in an old furnace. A crack or rot can cause carbon monoxide poisoning which can kill you. Or make you very sick.
 
Houston204, mikehende, Norm201 voted this post useful.
  #13  
Old 12-24-22, 06:37 AM
M
Member
Thread Starter
Join Date: Jan 2006
Location: NYC
Posts: 668
Received 5 Upvotes on 5 Posts
Thanks. I know another local repair guy who had repaired a bud's boiler last year who can do a checkup but wondering if I should call him "now" or wait unto after the winter or just before next winter please?
 
  #14  
Old 12-25-22, 09:14 AM
H
Member
Join Date: Nov 2012
Location: USA
Posts: 2,245
Received 277 Upvotes on 237 Posts
Originally Posted by mikehende
but on super cold and especially windy days, how high should I set it so as not to put too much strain on the heating system please?
Originally Posted by Geochurchi
​​​​​​setting the stat higher will just make the heater run longer to try and maintain the set point
I generally agree with Geochurchi-
BUT- if you have plumbing in or along an exterior wall (especially an addition) THEN you WILL want to up the temperature in that room (depending on how well insulated the wet-wall is).

Consider if you have an interior temperature of 72F and it is 32F outside, heat flow though the wall will put the center of the wall at around 52F (halfway between the inside / outside temperature). If you get down to single digits, say 2F then pipes in the center of the wall will start to freeze if the interior temperature drops below 62F, as the interior of the wall drops to 32set F. (Yes, this is a MAJOR oversimplification).

This is DRASTICALLY magnified if you have direct cold air drafts (e.g. you feel cold air leaking in through electric outlets). Oddly enough, this ALSO means that the normal best practice of "sealing electric outlets" can backfire because the cold air can 'fill up' the interior wall space and find its way to pipes in that wall.
 
mikehende voted this post useful.
  #15  
Old 12-25-22, 04:53 PM
S
Member
Join Date: Dec 2022
Posts: 30
Received 1 Upvote on 1 Post
Here is what I would do for an old furnace.

1. Buy a carbon monoxide detector and ut it close to the old furnace.

2. Do not tamper with it unless it is broken.

3. Set the shut off furnace temperature not too high. Let the furnace run a bit cooler when running.

4. Set the blower turn on temperature a bit lower.

5. Increase blower fan speed. That will run the heat exchanger a bit cooler

Basically make furnace run NOT TOO HOT.
 
mikehende voted this post useful.
  #16  
Old 12-26-22, 04:42 AM
M
Member
Thread Starter
Join Date: Jan 2006
Location: NYC
Posts: 668
Received 5 Upvotes on 5 Posts
Thanks Sam, will mention all that you've written whenever I should someone come here to do maintenance.

However guys, I am always a prevention is better than cure kind of guy so my belief is in checking the system "before" the winter season at least every couple of years, replacing any parts which might start showing signs of breakage, anyone here agree with this please?
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: