Majestic CFDV PI wont stay lit

Does the system have a standing pilot or does it use spark ignition with a control board ? I'm guessing you cant tell if the pilot goes out when the main burner goes out ?

Sort of sounds like a thermocouple?

The fireplace manual is at:

https://www.manualslib.com/products/Vermont-Castings-36cfdvpi-3840581.html

Does the pilot burner shut off when you turn off the burner?

The manual suggests there are conditions in which that might cause the fireplace to repeatedly cycle on and off when it's starting up. The cause can be a cold fireplace which prevents combustion air from circulating until the fireplace heats up.

The suggested fix is to use the option to keep the pilot burning all the time, thus keeping the firebox with a degree of warmth to it, allowing it to begin venting immediately:

From the manual:

COLD CLIMATE OPTION (IPI Models Only)NOTE: If you live in a cold climate, seal all cracks aroundyour appliance and wherever cold air could enter the room,with noncombustible material. It is especially important toinsulate the outside chase cavity between the studs andunder the floor on which the appliance rests, if the floor isabove ground level.Your fireplace is equipped with an intermittent pilot ignition(IPI) control. An IPI control with a standing pilot option pro-vides the dual benefit of an economical and environmentallyresponsible product and one which lights easily even inthe coldest climates. When in intermittent pilot mode (asit comes from the factory), your pilot remains unlit untilneeded, saving you fuel. Standing pilot mode, by com-parison, is characterized by a continuously burning pilot.The benefit of a pilot which lights only when needed is fuelsavings. However, with no pilot burning in your fireplace,units operating in colder climates may experience delayedstart up or lock out. Because colder air is heavier thanmilder air and there is no pilot burning to maintain a warmstable temperature in your firebox, establishing a draft toaid ignition becomes difficult. This is perfectly normal butcan be somewhat frustrating.To remedy this issue, your fireplace has been designed witha cold climate pilot option, which, when active, maintainsa warmer temperature inside your firebox to make ignitio

Wooduser, that little piece out the manual is the exact scenario I was referring to when having the venting in a cold chase.

The ideal solution would be a gas valve that only flowed a little gas when lighting and then slowly ramped it up as the flue warmed. Seems the manufacturers are reluctant to spend the money on a valve with better control capability. Instead they rely on a control bord with a strategy to try re-lighting several tomes to resolve the problem.

KeithO said:

Wooduser, that little piece out the manual is the exact scenario I was referring to when having the venting in a cold chase.

The ideal solution would be a gas valve that only flowed a little gas when lighting and then slowly ramped it up as the flue warmed. Seems the manufacturers are reluctant to spend the money on a valve with better control capability. Instead they rely on a control bord with a strategy to try re-lighting several tomes to resolve the problem.

Click to expand...

In the good old days, electric gas valve manufacturers used to offer "slow opening" gas valves, that would do just that and could avoid blowing out pilot lights and such.

Haven't seen one of them in many a year!

When I saw the piece I quoted I thought it might help explain a number of ignition related problems that have cropped up here in recent weeks.

I had earlier denied that it should be necessary to do such things as hold a propane torch inside a modern gas fireplace to get it to vent, asserting that they were designed to operate properly without such help.

So when I saw the piece I quoted, it was an admission that cold weather could create such problems. In any case, around Seattle getting what many people would call "cold weather" is a rare event.

Well, that's the new thing I learned today. In my days as a gas fireplace repairman, I didn't always fix things the first time, but if I didn't I was anxious to learn why I didn't and figure out how to do things better the next time.

It also illustrates the value of reading manufacturers installation and operating manuals carefully. There are often little nuggets in them if you read them carefully, and it's a pleasure to see how often they can easily be found on line.