Lennox furnace keeps throwing rollout code while Central Boiler calls for blower

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Nail Pounder

New Member
Dec 19, 2021
2
Michigan
I have a g26 Lennox LP furnace, and a 6048 central boiler. The Lennox is on the primary thermostat its setting is at 65 degrees, and the boiler is on the second thermostat with temp at 74 degrees. It works OK for a while; then it starts acting up, the combustion air blower will start and stop. When the supply air blower starts sometime it will stay running, sometimes the combustion air fan will keep starting and stopping eventually shutting the furnace down, not sure if it the Watchguard-Flame Failure Mode that activates or just the rollout error. I can turn power off to furnace for about 2 minutes to reset and it will work. If I push on the circuit board, or the frame it will start. The Molex plug seems to be OK I can push on it and it won't stop. Not sure if the circuit board need to be changed. The rollout switch has 28v on both wires and the button doesn't trip, not sure why the rollout error code keeps coming up and shutting down the furnace. I cleaned the filter it wasn't dirty.
Well I hope that's enough information. Thank You for you help.
 
The LP thermostat is a Honeywell CT2800a1009. The Furnace Y to Y, furnace G and boiler t-stat W to G, furnace R to R, boiler t-stat RH to RC. The Boiler t-stat is a central boiler (White Rogers) M# 1F78-144 G jumper to W, RC jumper on RH. The manual say's on the Honeywell that the R and RC have a jumper wire between the two.