I tried replacing the batteries twice. The first time the thermostat worked
fine for a couple hours but after that it shuts off and says 'lo bat'. I
referred to the users manual and got nothing.
In my furnace, if the safety decides to disconnect it stops juice to the
thermostat which then runs down the back up battery and end up with drained
battery. Usually happens if condensation pump sticks and overflow tells
furnace to turn off. If you have a condensation pump check the sump to see
if it is full. Otherwise you may have a more significant furnace problem.
Condensation pump floats often stick due to algae and sump needs to be
cleaned once in a while.
Hard to believe that you allow the condensate pump to shut down your
furnace. What's the better option---some water on the floor or frozen
pipes? Do you actually spend time away in the winter unconcerned that a
"sticky" float could trigger frozen pipes?
When lo battery is indicated it has few more days juice left to
function. Use good Alkaline ones. If it keeps doing that maybe something
wrong with the 'stat; like cracked solder joint/PCB trace, etc.
Had same problem with same stat. This worked for me. Pull cover. heat/off/cool
switch to off. Remove batteries. remove red and white wires (which supply 24
volts to the circuit) hit reset button. Wait 20 minutes. restore red and white
wires, put in batteries. Hit reset again. Wait 2 minutes and it should work.
Basically cut all power for a while and reinstall. Manual apparently states
batteries should be replaced with switch in off position but my quess is most
people don't read the manual. This looks like a basic software bug. Good luck.
replying to RDemarest, robert wrote:
I wrote the above and thought it worked. No, it was working less than a day. You
have to replace the electrolytic capacitor. It is the only component that
degrades with time. Mine now works.
replying to sofireme, robert wrote:
I solved the problem by replacing the sole electrolytic capacitor. Works again.
original capacitor was 1000 uf 6 volts. I replaced with 1000 uf at 10 volts
which is slightly bigger but the 6 volt one would work. I had the part and a
replying to sofireme, robert wrote:
Find someone with a soldering iron and replace capacitor. Should cost about 30
cents on line. I spent quitr some time on research and ended up buying a new
thermostat but did repair my RobertShaw in about two minutes.
replying to robert, Douglas wrote:
At the risk of sounding foolish, I discovered my thermostat does not like
Duracell batteries. Convinced that maybe I just had a bad pack, I opened a new
one. Still no good. On a whim, I slipped in another brand that I found loose in
a drawer. I have no explanation for this, other than it worked.
You do not sound foolish, at all!
I've had similar probs with copper-tops. I bought some brand new
Duracell AA bats and put 'em in my brand new Maglite. Came out to my
van at O dark thirty and turned on my brand new everything flashlight.
It was a dark Wintery morning, jes below freezing. The Duracells
would not light! Not even faintly.
later that day, I bought brand new Energizers and put them in my Maglite.
Very next morning, it was about the same time and temp (dark, jes
below freezing) and the flashlight lit up jes fine. I've never bought
another Duracell, again.
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