St Croix Hastings Room Fan Stays On

Is it just the room air fan staying on after shutdown or also the exhaust fan?

 

Is your stove built after 2003? And have a digital control board? If so,it HAS to have a "proof of fire " switch, which other companies call a low limit or fan switch. It will be mounted very near the combustion blower,2 wires. Replace it. 80P20038-R

 

Here is a link to a manual.Could not post manual here because it is "restricted", but you can still download it.
blob:resource://pdf.js/dcb8840e-1b43-4eec-8363-1ffbd6d9b1c9#filename=Digital%20Control%20Board%20Service%20Manual%201_09.pdf

https://stcroixstoves.com/wp-content/uploads/2020/03/Digital-Control-Board-Manual-1.pdf

 

Both fans stay on.

 

Thanks Guys. I have seen the manual, but I didn't know the proof of fire switch is also the low limit switch. That could be another easy fix. I'll order that in the morning.

 

ok. I replaced the proof of fire switch, aka the low limit switch. The stove started and shut down normally. Two switches and a fire pot later, I'm into this for about $200. Hopefully I'm done. Thanks!

 

Many stoves DO USE a snap disc to turn the room air (Convection fan) on once the heat box gets up to temperature...

Get the stove apart and CAREFULLY see which snap disc runs the room air fan...
If the fan comes on when the stove is plugged in.....UNPLUG THE STOVE AND THEN DISCONNECT THE SNAP DISC ON THE HEAT BOX.....ISOLATE AND WIRES TO PREVENT A SHORT....PLUG THE STOVE IN... FAN SHOULD NOT RUN.

REPLACE THE SNAP DISC......

The fan snap disc operates every time the stove is run and warmed up......these discs are a BIMETAL (2 DIFFERENT METALS) and this causes them to deform and operate the switch function.

If the snap disc with the reset is tripping.....This is usually a HIGH limit snap...

The high limit snap disc normally shuts off fuel flow in the event of an over fire condition.

STOVE WAAAAAAY TOO HOT

If the only issue is the room fan not shutting off.....room fan disc failure is the likely issue.

I am not familiar with that particular stove.....but I assume the room fan comes on after the fire has been burning for a bit ??????

 

At this point, both switches have been replaced. I tested shutting it down once and everything worked properly. Since then, it's been single digit temperatures here, so that thing has been running steady! Thanks for the in put!

 

I just scared up a schematic

The low limit snap disc....two brown wires and the disc may be located on the exhaust fan housing.
WITH STOVE UNPLUGGED (Cold stove)
Disconnect the brown wires at the snap disc....Use a VOM and check the disc terminals for continuity .....COLD STOVE THIS SNAP DISC SHOULD BE OPEN If it shows continuity across the terminals this is likely the issue...

The Schematic only shows basic wiring.....the inner goodies are all kept out of the open world..


If the switch shows closed when the stove is cold and the fan runs.....disconnect one brown wire at the disc (Always have stove unplugged when inside the cabinet)
Plug stove back in.....Does fan still come on ????

As mentioned....the low limit (proof of fire) snap may well trigger the room fan.

A failed CLOSED low limit snap can cause what you are experiencing..

In many stoves the proof of fire (Low limit disc) is tied in with a startup circuit and if the disc does not close the circuit withing a specific time ....the stove will shut off.

A failed closed disc will still allow the stove to operate .....but if my theory is correct the room fan still running is an indicator of a failed low limit snap.... Also...the time that the stove took longer to turn off the fan....another indicator of a failing snap disc.....The disc only runs 5 volts DC ....the disc likely feeds a relay on the board that tuns on the fan and also keeps main power to the feed/timer circuits after the startup timer has dropped out.


Keep us in the loop...

 

"Keep us in the loop..."
His stove has been fixed.

 

Please do check the low limit switch......I would like to know if it was/is stuck in the closed position.

THANKS

 

Thank you for the help Snowy. Both discs have been replaced and the old ones tossed out. The high limit disc was replaced first, but didn't solve the problem. The low limit disc was next, and all is well.

 

Sweeeeeeeeeet
That make life good.....

 

Being the 'hoarder I am', I always buy multiples of stuff and keep a spare set on hand in the shop, where they ultimately get misplaced...lol