LP vented insert with or without a blower- same heat produced?? what???

[Lakenouse man]

Hello, New to the forum and I appreciate any help I can get.

I have a couple vented LP gas inserts and a few vental Natural gas inserts at various properties.

On one of my LP gas inserts, I noticed that the blower fan is cycling every couple minutes. I understand, depending on proper thermodisc operation, the blower should turn off when the box cools down but in the case, it is clear the fan motor is cycling on and off for no reason. I replaced the thermodisc thinking it might be the problem and I still have the cycling problem. I am going to proceed to replace the blower motor at this point.

However, this really isn't the question. I spoke to a local service company who sells tons of inserts and I have known them for many years. They are well respected in the community. The owner of the company told me point blank that whether or not you have a blower fan installed on a vented gas insert, the amount of heat put out into the room is the same. This makes no sense to me as you can stand in front of the unit with the blower fan on and it feels like a blast furnace. Turn the fan off and you can feel very little....what am I missing????

 

[wooduser]

Hello, New to the forum and I appreciate any help I can get.

I have a couple vented LP gas inserts and a few vental Natural gas inserts at various properties.

On one of my LP gas inserts, I noticed that the blower fan is cycling every couple minutes. I understand, depending on proper thermodisc operation, the blower should turn off when the box cools down but in the case, it is clear the fan motor is cycling on and off for no reason. I replaced the thermodisc thinking it might be the problem and I still have the cycling problem. I am going to proceed to replace the blower motor at this point.

However, this really isn't the question. I spoke to a local service company who sells tons of inserts and I have known them for many years. They are well respected in the community. The owner of the company told me point blank that whether or not you have a blower fan installed on a vented gas insert, the amount of heat put out into the room is the same. This makes no sense to me as you can stand in front of the unit with the blower fan on and it feels like a blast furnace. Turn the fan off and you can feel very little....what am I missing????

Both you and your service agency rep might be correct.

The identical BTU gas input to the fireplace occurs whether than fan is on or off. That's determined by the gas pressure supplied to the main burner by the electric gas valve, which is unaffected by the operation of the fan. So your service provider is correct on that issue.

However, especially with a fireplace insert, you might get a little more heat out of the fireplace with a fan on than with it off. The fan help extract a little more heat from the hot combustion chamber. But it's probably not much, although it may feel like quite a bit if you are standing in the path of that warm air stream. Without the fan on, the hot air flows up by convection towards the ceiling, and while it's heating the room, it may not feel as warm as when the fan is on and you are standing in that warm air flow!

I did gas fireplace repairs for many years, and frankly I was not a fan of fireplace fans. I thought they were overpriced, hard to install and remove and therefore usually neglected and plugged with dust and dirt that never got cleaned out.

My personal bias with the wood stove I operate is to use a box fan to break up convection heat layers, mixing room air into a uniform temperature.