33 means a LIMIT OR FLAME ROLL-OUT SWITCH IS OPEN -
- Dirty filter or restricted duct system. - Loose blower wheel.
- Defective blower motor or capacitor. - Defective switch or connections.
- Inadequate combustion air supply (Flame roll-out switch or fuse link open).
- Open flame roll-out switch, or fuse link. Manual reset or replace.
There may be
several limits on the furnace.Blow describes locations:
The pri***** *****mit control is located on the partition panel and monitors
heat exchanger compartment temperatures. It is a normallyclosed
(electrically), automatic reset, temperature-activated sensor.
The limit guards against the overheating as a result of insufficient
conditioned air passing over the heat exchanger.
The auxiliary limit control(s) are located on or near the circulator
blower and monitors heat exchanger compartment temperatures.
They are a normally-closed (electrically), manual-reset, temperature
activated sensors. These limits guard against overheating as a
result of insufficient conditioned air passing over the heat exchanger.
The rollout limit controls are mounted on the burner/manifold assembly
and monitor the burner flame. They are normally-closed
(electrically), manual-reset, temperature-activated sensors. These
limits guard against burner flames not being properly drawn into the
Lets start by checking filters, then we will move to the manual switches near burners.Red button in center will push in t reset.We will go from here.