Auqastat Honeywell l8148e damper jumper plug

MarcusW

Hello everyone. I'm new to the site as a member but have used the site many times over the years to troubleshoot various heating problems so thanks in advance. I'm trying to start a boiler without the damper installed. For trouble shooting purposes I wanted to know if the damper plug with jumper wire installed has anything to do with me not getting power at terminals b1 and b2 for burner. I have performed tests with my multimeter and I have line voltage l1 l2 and have my necessary voltage at t1 t2 and verified 24 volts coming off the transformer. Thanks

icesailor

The question is, is the 24 volt to the damper motor part of a 24 volt safety circuit> That in order for the burner to start, does the damper have to be in the open position so it can't start without the flue being open?

Tim McElwain

When the first call for heat with the damper connected to the L8148E took place an internal fuse is blown in the relay. That prevents using the system after that if the damper is not connected. A temporary solution provided the damper is open or removed is to jump the two middle terminals on the damper connection on the relay, that will allow normal operation of the relay without the damper connected. This is not unsafe in fact if you need it I have a factory bulletin authorizing it by a well know manufacturer.

Ironman

If the plug was ever removed and a damper connected, it intentionally blows an internal fuse link so that the control will not allow the burner to fire without the damper connected and in the open position.

MarcusW

If the fuse blows at startup do i now have to repair the blown fuse in order to install the damper.Thanks everyone. Wanted to make sure before I bought a new stat. I understand that the damper is there for effeciency and safety.Jumping the pins make sense so at least I can verify that the boiler is still good.

Tim McElwain

The fuse can not be replaced as its blowing on initial startup makes it so that the system will not operate and have a closed damper causing an unsafe condition. Get rid of the damper if you so choose and leave the jumper in place on the L8148E or replace the L8148E with an L8148J (Universal Replacement Relay) which has no damper hookup.

unclejohn

Someone tell him that HE HAS TO REMOVE THE damper before he jumpers out the plug. It's not a choice thing.

NYplumber

Tim, can you please post or email me the document you mention.

When jumping the damper out, its always best to remove the damper and install a piece of vent pipe in its place. If the flap should close when a home owner is tinkering, exhaust spillage will result.

Tim McElwain

E-mail me at gastc@cox.net and I will send it to you.