"JRStern" wrote in message
...
When can these things be repaired, versus being replaced?

Forced-air gas heater didn't seem to be sending up any heat today, so
I cycled it a bunch of times, then finally descended to the 10x10
basement where it lives. Flame would come on, after a minute or three,
stay on for 10 seconds, then go out again. Blower kept blowing.

System was working fine two days ago - but for some years, it has had
the habit of turning on only slowly, after a minute or three of
waiting.

So I called one of the big chain repair places, they came in, popped
off the cover, told me the pilot was getting sucked away, and this was
a sign that the whole thing needs replacing, for about $10k. Plus,
the water heater looks like it's had a couple of leaks, might want to
replace it, too, for another $1,500.

Heat/Air is a Carrier unit circa 1984 (house much older), so it's not
like a newer, higher-efficiency unit might not be a good idea anyway.
Not sure of the water heater age, probably not that old.

This is a unit for a 2,000sqft house in suburban Los Angeles.

What surprises me is how quick the repair guys went to "Replace!".
Can't these things be repaired? How complex is a gas furnace anyway?

The repair guys seemed to know their business, I just wonder how much
of their business is doing replacement rather than repair, if you know
what I mean.

Me being a total newbie on this, any advice appreciated.

Thanks.

Someone mentioned buying a controller from Graingers for $35. I'd like to
see THAT!!
You can get a generic controller for about $100 from White-Rodgers, but
without a flame probe, and you will proly have to add extra blower relays.

If I understood the problem correctly, the flame going out is not a pilot
problem -- a pilot problem would prevent any ignition. The problem (now) is
the flame doesn't stay on, which could mean a flame probe/sensor problem.
Flame probes cost anywhere from $25 to $100.

Which doesn't mean the exchanger is *not* cracked, but I think this is dicey
to diagnose, as blowers can stir up ambient air around them as well, making
match/smoke tests difficult to assess.

Rewiring a furnace is not rocket science, but it does requre some
familiarity with basic electricity, relays, etc.
--
EA




Josh