"Hamilton Audio" wrote in message
news:nPGCd.695239$Pl.480658@pd7tw1no...
my 10 year old gas fireplace has recently given me trouble with turning on
and off. when I moved here, the house had a simple wall switch that
turned the fireplace on and off. I subsequently wired an inexpensive
manual thermostat in series with the switch. Thus, the switch was the
master control - ON had the tstat controlling the fireplace. OFF was off
it has worked well for 1.5 years.....
anyway, problem with intermittent no-start. I take my first look under
the fireplace and the wiring was a joke. It is some kind of
braided/insulated single strand copper stuff running all over the place.
a basic on/off switch in the middle with a bunch of stuff taped and jigged
up....not good. I noticed that jiggling the wires from the hi-limit switch
caused the fire to jump. In the end I got brave and removed much of the
old, brittle wiring and am left with a bare gas valve and two wires from
what I think to be a dead hi-limit switch. I removed all of the excess
wire that was wrapped around the gas lines and in behind the blower for no
reason....
right now I've got the pair of tstat/switch wires (from the wall) directly
jumpered to the two terminals on the gas valve, and the unit works
perfectly. switches on and off instantly.....having traced the wiring
diagram several times, all I can see is they had the hi-limit switch and a
microsswitch inline....am I missing something here?
questions:
1. the high limit switch shows continuity, yet when wired in series with
the gas valve, will not allow the fire to start. huh? Should I not be
able to run the high limit switch in series with one side of the tstat
control wires (say the white one) and have it work? because it doesn't -
yet shows continuity....and then will "sometimes" allow the fire to
start....
2. the cheep wall thermostat - shows continuity when triggered, and open
when not (as you might expect). however, it will NOT turn on the
fireplace. If I manually short the leads and get the fire going, it will
hold the fire on and turn it off..... again, huh? it workd for over a
year perfect...clearly it has failed. didn't know they failed???
3. wiring - does any code or anything apply here (Ontario, Canada)? does
there have to be a certain style or type of electrical wiring underneath
the fireplace? or can I use the simple 16 awg. insulated primary wire
(used in car audio) for this app? I'm using it right now for testing with
no problems, but don't want to get into a code issue should a problem
arise in the future....
I've tried the tstat right at the gas valve (bypassing the wiring in the
wall) and it behaves the same. I'm going to get a new digital unit
tomorrow, this I know....but does anybody out there have any thoughts on
questions 1 and 3? My thinking is bad tstat, and bad hi limit switch
mixed with crusty old wiring....
thanks!
b
I fixed one of these things that had a bad switch too. Luckily the switch
was DPST so I could just move the wires over to the other side. Ringing out
the switch won't help if it's intermittant unless you get lucky and catch it
acting up....good luck, Ross