Direct-vent without thermocouple

[logdoc_rob]

I was having a cold brew with a co-worker and we were discussing thermocouples in direct-vent gas fireplaces. He said he has customers with Heat-n-Glo DV without a thermocouple. I think he said it was a SL-750. I don't recall running across any of these beasts and they don't sound like I would want one installed in my home without a quick drop out TC.

Was he mistaken in what he saw and what other DV have no TC, only a TP?

[jtp10181]

Very common in old fireplaces. It was a 2 minute drop out valve (With a TC its a 30 second drop out). The lower TP connection has an EPU wire that plugs into the back of the valve (where the TC usually goes).

Not sure what the reason for using them was? They are still considered safe, if one of the valves goes bad we just replace it with another of the same style.

[logdoc_rob]

I guess that in life things used to be safe that are not seen as safe now. I remember when sex was safe and race cars were not!!!

[hearthman]

Introduced in 1995, which required a 30 second pilot dropout. Prior to that, gas fireplaces listed under ANSI Z21.50 used a thermopile only which had a dropout rate of 3 minutes. There were a few incidents where a flame went out but the pilot remained hissing gas, the homeowner went over to relight the pilot and BOOM!

BTW, you may have modern gas DVs without thermocouples: electronic ignition such as IPI, DSI, and HSI. Just no TP either

HTH,
Hearthman

[logdoc_rob]

Yes, there are a lot of DVs in this area with IPI and DSI, but I have only run across one with HSI in the past 10 years. Those ones made before 1995 scare me almost as much as log lighters !!!!