SURE MARINE SERVICE INC.

This troubleshooting guide was written specifically for Seaward / Princess / Hillerange stoves manufactured prior to September 2007 It is applicable to many other brands of RV & marine stoves including many Magic Chef, Wedgewood, Kenyon, & early Gas Systems ovens. Starting in mid 2007 Seaward redesigned their oven controls, eliminating the mercury control valve and making this troubleshooting guide not applicable. It is only meant as a guide & does not cover every possible issue. Feel free to contact Sure Marine if you require assistance or parts at (206) 784-9903. The basic oven components are the oven thermostat, the mercury control valve, the pilot assembly and the main oven burner Later versions are also equipped with an oven thermocouple & safety valve. All Seaward / Princess / Hillerange stoves built after 1993 should have an oven thermocouple & safety valve. Stoves built between 1984 & 1993 might have an oven thermocouple & safety valve. If simply turning the oven control knob allows gas to exit the pilot assembly there would be no 'oven thermocouple'. Most stoves built prior to 1984 would operate this way. If you do have an oven thermocouple, you would need to depress a button in order to light the pilot. Generally you need to hold the button for about 10 seconds after the pilot is lit, then release the button and the pilot stays on. The 'safety valve' and 'oven thermocouple' only effect the pilot staying lit, so if you can get your pilot light to stay lit these parts are not the issue. If your stove is equipped with an 'oven thermocouple', you should be able to see a threaded probe mounted directly above the pilot flame. If you are having trouble getting the pilot to stay lit after you release the push button, verify that the tip of the probe is covered with flame in the 'low pilot mode'. If the probe is in the flame, but the pilot flame goes out as soon as you release the button, there are a few possible causes. The thermocouple could be defective. ( a thermocouple is an electrical device that generates a small voltage when heated. ) The electromagnet inside the safety valve could be defective. ( The safety valve has the push button you need to depress when lighting the pilot ). You could have a bad connection between the thermocouple & safety valve ( loosens with a 5/16" wrench, wire brush end & reassemble. Don't over tighten ) The 'oven thermostat' monitors the oven temperature using a sensing probe usually located in the top rear of the oven. It compares the oven temperature to the temperature you have selected with the oven dial. It modulates the pilot flame height up to 'high pilot' when there is need for more heat, & down to 'low pilot' when the oven is at temperature. That is basically all it does. In the "oven off" position it also blocks gas going to the 'mercury control valve'. During normal operation, the only component physically blocking gas to the main burner is the 'mercury control valve' The 'mercury control valve' monitors the pilot height using a small probe mounted in the end of the pilot assembly. When it senses a large pilot flame ( oven thermostat has sensed a need for more heat ), the 'mercury control valve' opens and allows gas to flow to the 'main oven burner'. The 'mercury control valve' itself is normally located directly behind the thermostat, but in early stoves it can be mounted in the wall of the oven. It is often replaced by the customers due to a misdiagnoses of an oven problem. The 'mercury control valve' acts as a safety feature, if there is no pilot flame present in the oven, it prevents a large amount of gas from entering the oven cavity. If you can get the pilot to light, and you can get the main burner to come on, but periodically everything, including the pilot light goes out, you probably have dirt in the pilot orifice. The pilot orifice is located at the inlet to the pilot assembly behind the 3/16" compression nut ( requires 7/16" wrench ). This problem could also be caused by a bent pilot assembly, low gas pressure or a sticking propane regulator. If running a top burner while operating the oven eliminates the problem it would point towards a sticking propane regulator. If your stove is equipped with an 'oven thermocouple', verify that the thermocouple's probe is directly over the flame in 'low pilot' mode. If the main burner does not light, but the pilot does stay lit, you need to check a couple things. Verify you have two distinct flame heights on the pilot, 'low pilot height' when the oven is up to temperature ( or in pilot only setting ), and 'high pilot height' when the oven is colder than thermostat setting. ( ie. oven cold & control knob set to 500F ). Try lighting the pilot, and turning the control knob up and down, You should see the two different pilot flame heights. If the flame goes out when transitioning between the two flame heights, there is probably dirt in the pilot orifice or you have a bent pilot assembly. These are common problems. If you only have a 'low pilot height' at all temperature settings, then you have a defective thermostat. If you have two pilot flame heights, but the main burner doesn't come on, it is often dirt in the pilot orifice. Try turning the thermostat up until you achieve 'high pilot height', take your lighter and apply additional heat to the probe located in the end if the pilot assembly. This is the probe connected to the 'mercury control valve'. If the burner comes on, then the pilot flame just wasn't quite hot enough. Again, this is probably dirt in the pilot orifice, but could also be caused by a bent pilot assembly, mis-located probe or low gas pressure. If you have the thermostat turned up, and the pilot size is big, and you apply additional heat to the probe but the main burner still won't light, you probably have a defective mercury control valve. In a Seaward / Princess / Hillerange, if the mercury control valve is located on top of the stove it is part #72532. If the mercury control valve is located in the side wall of the oven, it is probably part # 70402. There are several variation besides these common two. The 72532 & 70402 are both factory discontinued items, there are a limited number of remanufactured units available, Some of the remanufactured units require modification of the supply lines. Call for availability. A new pilot orifice is part #70392 for LPG. #70393 for CNG You can possibly clean / blow through the pilot orifice and reinstall it. The hole is tiny, don't stick a needle in it or you will probably ruin it. To remove the pilot orifice, start by removing the propane line using a 7/16" wrench. The orifice may simply fall out, or you may need to pry it out using a nail or small screwdriver. It's shaped like a tiny thimble. Insert the tool through an air hole located just beyond the threads past where the propane line was removed. Use caution as the orifice is easily damaged. If your oven does not have automatic spark ignition you can turn on the oven control briefly to blow out the supply line in case there is more dirt inside the line. If you need to replace the oven thermostat, many styles have been discontinued. There is a replacement thermostat kit available, but it may require several modifications The only thermostat being remanufactured is the #70400. It is shown in the last two photographs on this page. It can be identified by the triangular shaped plate attached to the rear of the thermostat body. If you can not positively identify your stove in the pictures on this page, take a few photos and email them to us so we can be certain you get the right parts the first time. Many parts are only available remanufactured and require modifications / adapters etc.

Sure Marine Service Inc.
5320 28th Avenue NW, Seattle, Washington 98107
800-562-7797, 206-784-9903, Fax: 206-784-0506