On Wed, 10 Dec 2008 22:01:38 -0600, (Lp1331 1p1331)
wrote:

A couple of points on replacing hot surface ignitors--I have heard that
you should not touch the actual ignitor surface ( oil from your fingers
can damage it), and have also heard that is not true. Regardless, it
sure couldn't help one, so to be safe. just handle it by the block only.
Also, after you get it in place, check VERY carefully, using a mirror if
necessary, that the ignitor is not touching the burner or heat
exchanger. Last yeaar I replaced one on a Trane ( same thing as American
Standard), didn't notice that somehow it was touching one or the other,
and when it came on it looked like an arc welder. Luckily I didn't fry
the board along with the ignitor. About two years ago I went out on a
8-9 y/o Janitrol on a Sunday morning that another company had been to
the night before. The same thing had happened to them. They actually
charged the people a service call and left. They took the ignitor off
and took it with them. I put a new one on and found it wasn't getting
any power to it. Fried the board and I didn't have a new one. It was
real cold and the people had a very young infant. They were real close
to my house, so I went home and took the board out of my Janitrol
furnace and gave it to them-- just charged a service call and the
ignitor. I've gotten several boards since then from furnaces we have
replaced and one of these days will get around to sticking one of them
back into my furnace. I have dual fuel heat pumps and just stuck a relay
on it for the blower. Probably change the filter when I do the board
too. The old adage about the shoemaker's kids-- Larry


There are at least 2 technologies used for hot surface ignitors - and
the most common one is appently totally intollerant of abuse and more
expensive than the other one. One is silicon carbide, the other
silicon nitride. The silicon nitride is supposed to last 2 or 3 times
as long as the carbide.