I have not been able to get an answer i can understand to my electrical question about line volt. thermostats. The honeywell t451 has proven itself to be a very unreliable stat. So i bought 6 t498 electric heat thermostats and installed them at 6 different houses. They are working well, with no call backs. Before i install more i called honeywell to ask if this was ok to do?The answer they gave me was that the t451 is a "conductive" stat. & the t498 is a "resistive" stat. there for the 498 should not be used on oil hot water system. The lady i spoke to on the Honeywell tech. support line could explain further. Before i purchase any more and get myself in trouble what do you think.
Thank You in advance,
From Tom jr

Tom, I think they probably meant inductive, not conductive.
Inductive loads, involving motors, transformers, and relay coils, causes more arcing and require contacts that will withstand the increased wear.

Electric heat is a resistive load.

Ed

Tom,

I think Ed nailed it. The T498 has a rating of 22A noninductive (resistive), and nothing is listed about inductive load.

The T451 shows up in a '89 catalog and has an inductive rating of 4A Full Load @ 208/240/277, 24A Locked Rotor, and 7.2A resistive.

Ah, the difference a decade makes.

Al