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[email protected] February 16th 21 11:31 AM

Gas heat thermostat if no power
 

Last week we were without power an hour and a half during a very mild snow
storm. Luckily it was 9-10:30 am and 34F. But what if it was longer, at night
and colder? The system is York Borg Warned from 1965. Anyone know if there
is a way to manually turn the heat on?



--
Vasos Panagiotopoulos, Columbia'81+, Reagan, Mozart, Pindus
blog: panix.com/~vjp2/ruminatn.htm - = - web: panix.com/~vjp2/vasos.htm
facebook.com/vasjpan2 - linkedin.com/in/vasjpan02 - biostrategist.com
---{Nothing herein constitutes advice. Everything fully disclaimed.}---





Peter W. February 16th 21 12:20 PM

Gas heat thermostat if no power
 
Way too little information - what is needed:

Type of heat:

a) If there is no power, a furnace with a blower will not work, full stop.
b) If it is an hydronic boiler with a circulator, it will not work, full stop.
c) Anything with spark or hot surface ignition will not work. full stop.
d) If it is a steam boiler with a standard vent hood, standing pilot, and a millivolt-style thermostat (which was common enough in 1965), it will work as always, as it does not depend on line-level power.
e) If it is an old octopus furnace (obsolete in the 1930s, much less the 60s) as above, it will work as always as it does not depend on line-level power.
f) If it is a gravity hydronic system, millivolt stat and standing pilot, as above, it will work as always, as above.
g) No oil-fired system will work as it needs mains-power to run the gun and the ignitor.
h) And, obviously, electric power will not work.

Even if you have installed a modern thermostat on a millivolt system - the batteries inside the stat should maintain function power-failure or not. We change ours with the spring time-change every year, even though it is for a mod-con hydronic boiler with three circulators. But if the batteries go down, the stat goes down.

Peter Wieck
Melrose Park, PA

Rich February 16th 21 12:55 PM

Gas heat thermostat if no power
 
wrote:
Anyone know if there is a way to manually turn the heat on?


That depends upon what type of heat, a fact that you left out.

Tim R[_2_] February 16th 21 02:04 PM

Gas heat thermostat if no power
 
On Tuesday, February 16, 2021 at 7:55:39 AM UTC-5, Rich wrote:
wrote:
Anyone know if there is a way to manually turn the heat on?

That depends upon what type of heat, a fact that you left out.


Read Peter's post. it is extremely unlikely you have a system that will work. A low pressure (1 psi) steam system may work if it's the old single pipe system AND a thermopile or standing pilot. I haven't seen one in years.. I've lived in one farm house with an octopus and that might work.

Eli the Bearded February 16th 21 06:55 PM

Gas heat thermostat if no power
 
In sci.electronics.repair, Peter W. wrote:
e) If it is an old octopus furnace (obsolete in the 1930s, much less
the 60s) as above, it will work as always as it does not depend on
line-level power.


The gravity furnace[*] in my San Francisco house is much newer than the
1930s. From memory the nameplate is mid 1960s. I suspect -- this would
fall under "happened long before I lived here" -- that the building had
a gravity furnace installed when originally built (1906), or shortly
thereafter, and in the 1960s someone decided to replace the furnace but
didn't want to reduct, so just put in another gravity furnace.

I seriously dislike it, the lack of forced air means you can't have
filters, and the lack of filters means it smells of decades of
accumulated dust every time it is turned on. I think we ended up using
it only one or two days in the calendar year of 2020. It works, although
slowly, when we do turn it on, but mostly we find other ways to keep
warm.

The ducts are all asbestos insulated, so tearing it out won't be fun,
when the time comes. The thermostat is is one of the old mercury switch
types, probably installed at about the same time. Mercury switches are
fun.

Elijah
------[*] "octopus furnace" is a slangy name for "gravity furnance"

Peter W. February 16th 21 07:57 PM

Gas heat thermostat if no power
 
https://www.pinterest.com/pin/195343702562355034/

I never stated nor implied that Octopus furnaces were not made after the 1930s, but that they were obsolete thereafter. :-)

And, of course, those Transite and non-woven asbestos ducts do leach out such that a blower would spread ACMs everywhere. No fun at all.

We have a 4,200 s.f. center-hall colonial built in 1890, and substantially enlarged in 1928, with a gravity-designed hydronic heating system (4" ID main risers, 3" ID returns). Now it is served by a mod-con 97% efficient (by actual test) boiler. But heating the well over 300 gallons of water in the system (38 rads) is an ordeal on its own. So, we installed mini-splits last January followed by a visit from our gas/electric utility in April to see if we had diddled the meters. When they saw the equipment, they reported that all was well. Point being they heat and cool with a SEER of 29+. We run the house at a constant 60F for heating, and the six rooms that we use the most have the splits in them. Our combined gas and electric bills are less than $300 per month, on average at $0.14 per KWH, and $0.77 per therm. We use gas for cooking and hot water as well (indirect water heater from the boiler). I suspect that mini-splits in your case could solve the entire heating/cooling issue for less than the cost for the removal of the boiler. Just mothball it and seal the ducts.

Peter Wieck
Melrose Park, PA

Eli the Bearded February 16th 21 09:15 PM

Gas heat thermostat if no power
 
In sci.electronics.repair, Peter W. wrote:
I never stated nor implied that Octopus furnaces were not made after
the 1930s, but that they were obsolete thereafter. :-)


Noted, but I wanted to drive the point home.

And, of course, those Transite and non-woven asbestos ducts do leach
out such that a blower would spread ACMs everywhere. No fun at all.


It appears that the asbestos is on the outside of the ducts, not the
inside. At least the parts I can easily see all match that.

But heating the well over 300 gallons of water in the system (38 rads)
is an ordeal on its own.


What? In my mind "1 gray = 100 rads". That doesn't jibe with 300
gallons.

https://i.imgur.com/aLl7SFO.jpg

Our combined gas and electric bills are less than $300 per month, on
average at $0.14 per KWH, and $0.77 per therm. We use gas for cooking
and hot water as well (indirect water heater from the boiler). I
suspect that mini-splits in your case could solve the entire
heating/cooling issue for less than the cost for the removal of the
boiler.


We have used electric space heaters on maybe five days in the last three
months, and have been averaging $160, just over half of that, per month.
These have been some of the more expensive PG&E bills we've seen, too.
The cost of inaction is much less than the cost of action.

Just mothball it and seal the ducts.


The first big win for removal would be all of the usable space that can
be reclaimed from the furnace and ducting. (Ducts in the walls are not
counted here as "usable space". This thing occupies a good percentage of
the garage / basement space.) The second big win would be "not worrying
about the asbestos exposure risk" in the garage / basement.

Elijah
------
that bill includes electric car charging, too

Peter W. February 17th 21 12:33 PM

Gas heat thermostat if no power
 
38 radiators, average 1.8 gallons each = 68 gallons
0.652 gallons per foot of 4" pipe. 120 feet = 78.2 gallons
0.37 gallons per foot of 3" pipe. 120 feet = 44.4 gallons
0.135 gallons per foot of 1" pipe 400 feet = 54 gallons
0.0229 gallons per foot 3/4" pipe 500 feet = 11.5 gallons
Boiler Content, 2 gallons = 2 gallons

Comes to 258 gallons of water in the visible piping, 8 pairs of risers and the boiler itself. It does not count the expansion tank, piping in the crawl-spaces, or the piping around the boiler and indirect water heater. Just the original iron pipe. It is a 3-zone, 2-pipe system with 3 circulators. So, I think I am pretty safe using 300 gallons as a round number. Our boiler is a WM Ultra 230,000 BTU mod-con that replaced the 400,000 BTU steel oil-burner that was in place when we bought the house in 2008. The math was easy..

Average 6 hours of operation per day for 120 days as the base-line. And based on use-figures supplied by the realtor.
Oil at $2.50 gallon (130,000 BTU per gallon).
Natural gas at $0.77 per therm (100,000 BTU).
Oil Boiler at 55% efficiency (typical of a 1960s steel boiler measuring 6 feet cubic - really).
Gas boiler at 95% efficiency (published specifications)

(6 x 400,000)/130,000 = gallons per day. 18.4 gallons per day.
120 x 18.4 = 2,215 gallons per season - this is a backwards calculation from the supplied use figures.
288,000,000 BTUs expended
158,400,000 BTUs delivered
$5,537.50 expended on fuel.

For gas (NOTE: Work with the DELIVERED BTUs, not the hours of operation!):
158,400,000/0.95 = 166,736,842 BTUs to be expended.
Comes to 1,668 therms
Comes to $1,283.80 expended on fuel.

Comes to a seasonal savings of $4,254

As I did 60% of the work myself, using a registered master plumber and contractor to do the demolition and final inspections, the entire installation paid for itself in three (3) seasons. That includes the cost of replacing 17 radiators and three pairs of risers - the house sat empty for two years (REO) and the system was left full.

I did enjoy the reference to the Simpsons - so the joke was not lost on me.

"The coldest winter I ever saw was the summer I spent in San Francisco."
- Mark Twain

Peter Wieck
Melrose Park, PA

Jon Elson February 17th 21 09:00 PM

Gas heat thermostat if no power
 
wrote:


Last week we were without power an hour and a half during a very mild snow
storm. Luckily it was 9-10:30 am and 34F. But what if it was longer, at
night
and colder? The system is York Borg Warned from 1965. Anyone know if
there is a way to manually turn the heat on?



Can't say about your system. We have hydronic heat here (water-filled
baseboard radiators, a circulating pump, zone valves and 24 V AC gas valve.
The zone valves have a manual override catch that will lock them open. I
guess that was provided in case there was hope of convection, but I doubt it
would work on our system.

Some gas valves have a manual override to turn the gas on, but you'd need to
be VERY careful to not overheat the heat exchanger without the line-powered
fan or circulator.

What we did was disconnect the furnace from the hard-wired power and connect
to a generator. It is apparently illegal to have a furnace fed from a plug,
so we have to unwire and then rewire every power failure.

A gas-fired furnace doesn't draw very much electrical power.

Jon

Peter W. February 18th 21 03:29 PM

Gas heat thermostat if no power
 
We have a small 30A @ 240 VAC emergency generator. When it is in use, we run it to a 30A double-pole breaker in the panel, shutting off the main breaker at the same time. That will cover the freezer, refrigerator, boiler a few lights and other miscellaneous items as needed, without having to wire or unwire anything. The feed from the generator is 6/3 SJO cord, and the unit itself is grounded to a properly installed 8' ground rod. The three times we have had to use it for more than a couple of hours, it has worked nicely.. Usually, we run a single-ended extension cord to our neighbors for their refrigerator as well.

Peter Wieck
Melrose Park, PA

Jon Elson February 19th 21 02:47 AM

Gas heat thermostat if no power
 
Peter W. wrote:

We have a small 30A @ 240 VAC emergency generator. When it is in use, we
run it to a 30A double-pole breaker in the panel, shutting off the main
breaker at the same time. That will cover the freezer, refrigerator,
boiler a few lights and other miscellaneous items as needed, without
having to wire or unwire anything. The feed from the generator is 6/3 SJO
cord, and the unit itself is grounded to a properly installed 8' ground
rod. The three times we have had to use it for more than a couple of
hours, it has worked nicely. Usually, we run a single-ended extension cord
to our neighbors for their refrigerator as well.

Yes, we have a much smaller generator. We have only used it once for an
extended outage. It was WONDERFUL to have it, though. We ran extension
cords all through the house, and ran the refrigerator, freezer, cell phone
chargers and the furnace.

Since the events where this has been needed are so rare, having to rewire
the furnace is not a big deal. I'm more worried about the gas valve
thermocouple going out in the middle of the night.

Jon

Three Jeeps February 21st 21 10:18 PM

Gas heat thermostat if no power
 
On Thursday, February 18, 2021 at 10:29:25 AM UTC-5, Peter W. wrote:
We have a small 30A @ 240 VAC emergency generator. When it is in use, we run it to a 30A double-pole breaker in the panel, shutting off the main breaker at the same time. That will cover the freezer, refrigerator, boiler a few lights and other miscellaneous items as needed, without having to wire or unwire anything. The feed from the generator is 6/3 SJO cord, and the unit itself is grounded to a properly installed 8' ground rod. The three times we have had to use it for more than a couple of hours, it has worked nicely. Usually, we run a single-ended extension cord to our neighbors for their refrigerator as well.
Peter Wieck
Melrose Park, PA


I assume the 30A double-pole breaker is wired to be a transfer switch, else, bad things will happen when the power comes back on.
In your configuration, wont you need to drop some load at the load center as I assume all the devices in a 3-4 bedroom house would exceed the power output of the generator? Just re-read the post...30A@240 VAC...probably not..

Ralph Mowery[_3_] February 21st 21 11:09 PM

Gas heat thermostat if no power
 
In article ,
says...

I assume the 30A double-pole breaker is wired to be a transfer switch, else, bad things will happen when the power comes back on.
In your configuration, wont you need to drop some load at the load center as I assume all the devices in a 3-4 bedroom house would exceed the power output of the generator? Just re-read the post...30A@240 VAC...probably not.



Unless the power line going to your house is the only line down, the
small generators would most likely trip out their breakers due to trying
to power up other houses on the line.

I have a small generator 3.5 kw and another 5 Kw and I cut off all my
heavy current users such as the water heater and heatpump. I only use
one generator at a time as the 3.5 generator is propane powered and I
use it for short periods of time . If the power is out longer, I then
put gas in the 5 kw one and use it. That way I do not have to worry
about gas being left in the fuel system and gunning it up. The 5 Kw
unit will power the water heater if it is almost the only load other
than a few lights. That way I can heat the water and take a very quick
shower if needed. It will also let me use the electric stove for more
than one small burner.



Peter W. February 22nd 21 11:52 AM

Gas heat thermostat if no power
 
".... Shutting off the main breaker...."

We are a gas-fired, nearly-all-LED house. The loads I will drop for such an event are the hot-tub, the mini-splits, and the TV & audio solid-state electronics. Otherwise, there is more than enough capacity for lighting, refrigeration and heating.

Peter Wieck
Melrose Park, PA


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