Venter On - No Burner

Upon a call for heat, the venter motor should turn on. Once the Prover safety circuit is closed, the burner should fire. If it does not, follow these steps:


For SideShot Series, reset High Limit and see if burner fires.  If High Limit was tripped, investigate the cause of high heat. SS1 & SS1C High Limit resets are located inside the UC1 Control box. SS2 High Limit reset is located above the UC1 Control box, under the sliding cover.


Verify that LED #2 (Blue) is lit.


Yes, LED #2  (Blue) is lit: Verify that "call jumper" is connected from J1 to J2 on UC1 circuit board if using typical wiring where supply voltage from terminal 1 is routed to terminal 3 through “call jumper” then to 4 when appliance interlock relay makes. With call for heat established, verify that wiring is correct by measuring voltage between terminals 1 & 2 and 2 & 4 of UC1 terminal strip. Voltage should be the same in both cases, if not rewire per appropriate diagram or confirm burner control(s) are functioning properly. NOTE: If a different voltage source is provided to terminal 3 which is switched to terminal 4 or when using the A-B dry contacts, voltage measurements may not apply.  For millivolt installations make sure system Limits are reset and relight pilot.


No, LED #2 (Blue) is not lit:  Remove power from UC1 and push dip switch #9 up or “on” to deactivate Fan Prover status check. Remove P1 and P2 prover leads off of Fan Prover switch and jumper together. Reestablish power and call for heat. After Venter pre-purge, if set (up to 35 seconds), LED #2 (Blue) should light.


No, LED #2 (Blue) does not light: Replace UC1 circuit board, part number 950-8804.


Yes, LED #2 (Blue) lights up: The fan proving switch may not be closing, wiring connections are incorrect/broken or burner control(s) are not functioning properly.  With Venter running, verify that Venter performance is sufficient to close Fan Prover contacts by checking for continuity across switch.  IMPORTANT: After continuity check push dip switch #9 back down to “activate” Pre-Cycle Fan Prover status check unless using a SideShot SS1 Series or Draft Inducer with a PS1505 Fan Prover. Natural draft or winds may be sufficient to close the fan prover switch contacts prior to a call for heat on the SS1 or when using the PS1505 fan prover with a draft inducer. Keeping the Pre-Cycle Prover Status Check activated may cause nuisance lock-outs.  Replace Fan Prover leads from P1 and P2 back on Fan Proving switch.


No, continuity is not present: Confirm that burner is not firing at capacities or temperatures exceeding Venter limits. Check for excessive vent pipe runs, elbows directly on venter discharge, high winds, plugged / kinked Fan Prover sensing tube or a faulty Fan Prover switch. In-Forcer model’s intake screen and prefilter, if applicable, should be cleaned if necessary. If everything checks out okay, replace fan prover.


Yes, continuity present: Recheck wiring and burner control(s).