Frymaster Dean FPHD - Manual (Page 34)

HIGH EFFICIENCY DECATHLON SERIES GAS FRYERS
CHAPTER 1: SERVICE PROCEDURES
1-29
1.8.1 Ignition Failure (cont.)
The Electronic Circuits
If gas and electrical power are supplied to the fryer, the next most likely cause of ignition failure is a
problem in the 24 VAC circuit of fryers equipped with electronic ignition systems, or in the pilot
system for those without electronic ignition. If the fryer is equipped with a SUFF/UFF filtration
system, verify that the drain valve is fully closed. (The valve is equipped with a microswitch that
must be closed for power to reach the gas valve. The valve handle can appear to be closed when the
microswitch is open.) If the valve is fully closed, or the fryer does not have a filtration system, refer
to the troubleshooting guides in this chapter.
The Gas Valve
If the problem is not in the 24 VAC circuit or pilot system, it is most likely in the gas valve. Before
replacing the gas valve, refer to the troubleshooting guides in this chapter.
1.8.2 Improper Burner Function
In these instances, the burner ignites but exhibits abnormal characteristics, such as popping,
incomplete lighting of the burner, fluctuating flame intensity, and flames “rolling” out of the fryer.
Popping indicates delayed ignition. In most cases, the main gas valve is opening, but the burner is
not immediately lighting. When ignition does take place, excess gas ignites rapidly rather than
smoothly.
The primary causes of popping are:
1. low or fluctuating gas pressure,
2. misdirected or weak pilot flame,
3. clogged burner orifices,
4. clogged burner flame-transfer holes
5. clogged burners,
6. inadequate make-up air,
7. heat damage to the controller or ignition module,
8. an out-of-adjustment igniter or broken ignition wire,
9. a defective ignition module,
10. missing or misaligned burners,
11. clogged vent tube (causing incorrect gas pressure), or
12. make-up air is blowing down the flue.