Hot Surface Igniter issues....

Crispy

Twenty or so years ago we were lucky to become the owners of a Garland 30" residential kitchen range. We love it! Garland didn't stay in the residential appliance business long but a company, Adco Service did pick up their parts business so parts are available.

I am struggling with Hot Surface Igniters that don't last long. My understanding is, with this paticular appliance, if the igniter isn't pulling 3.3-3.6A, then the gas valve won't open. Our present igniter, the third one, didn't light the broiler today and sure enough, I got 2.9A with an amp clamp.

My question…. Are there different quality options with these things? Put another way, should I avoid generic units made in <insert country with low labor costs> and buy from <these guys>?

Granted, heating a chunk of silicon carbide to red hot over and over probably isn't a great design but I'm stuck with it. Anyone wrestled with these? Thanks in advance, C.

109A_5

Since your appliance has that specific current requirement for the igniter, you may have to sample a few different brands to find what works reliable for that application.

Are the Garland / Adco Service ones still available, they may be made specifically with the current requirement in mind and the more generic ones (although they may physically fit and get hot) may not work reliably.

109A_5

Are the Voltage and Current specifications published on the packaging or in a cross reference guide? I have not looked at one in a while.

EBEBRATT-Ed

They used to say not to touch the silicon carbide when installing. Those parts must be made by someone like Honeywell, Robert Shaw is big in the appliance end and their are a few others. Who makes the gas valve?

Crispy

I'm going to pay-up through Adco ($150). I'm glad to have them for our out-of-production Garland. I had to buy an electronic control box for the burners a few years back and they had it.

I did check and the last igniter was a year ago and was a Norton product for $22. Don't remember how I spec'ed it.

mattmia2

make sure the connections are all clean. if the socket or the connections to the wiring or even the terminals crimped to the wire are corroded you could get a lower current draw. i'd try measuring the cold resistance of the ignitor with the meter probes directly on it(scrape them in a little so they make a good connection) and through the wiring and socket.

109A_5

As much as modifications makes folks heads explode. If the equipment is in good condition and the Hot Surface Igniter is the only issue. And if the OEM Hot Surface Igniter is becoming unobtainium or excessively costly. And you just have to make up about 0.5 Amps to make a more reasonable substitute work. I would simply add a power resistor to the circuit. The power resistor would be wired in parallel with the Hot Surface Igniter.

Since you are only adding 0.5 Amps to the circuit (2.9 + 0.5 = 3.4) and the circuit needs 3.3-3.6A to open the Gas Valve I don't see any safety issue if the more reasonable substitute Hot Surface Igniter eventually fails. Since 0.5 Amps is not enough current to activate the Gas Valve.

I would use a 240 Ohm 100 Watt resistor and the appropriate wiring. This type of resistor needs to be mounted to a heatsink. But since the duty cycle of a Hot Surface Igniter is pretty low, you may get away with minimal heatsinking. There are other resistor types that could be used. Even a 60 Watt incandescent lamp. However the resistor may last forever and lamps are getting harder to get.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1905668#Comment_1905668

some oven controls operate the hsi igniter intermittently, others keep it energized as long as there is a call for heat.

in fact, some googling shows that the oven control assumes the current from the hsi means there is a source of ignition and uses that to open the gas valve, it doesn't explicitly prove flame so modifying the igniter to produce more current seems like an unsafe idea. if the ignitor breaks, the resistor might be enough to keep the valve open because the hold current is usually a lot less than the pull in current.

109A_5

I was just going by the parameters offered. It is just an idea, not proof of concept.

I would expect if a modification is done it should be thoroughly tested. If the Pull-in current versus Hold-in current is an issue there are other means to make it work. I try the simplest approach first.

The OP seems to like the appliance, probably does not want to deal with the junk offered now.

mattmia2

since all that stuff is constantly baked by the burner, my bet is on bad connections increasing the resistance of the ignitor circuit. you could replace the whole gas chain with a direct spark ignition control and valve and flame rod too. those almost always have a t-stat that just switches 120v to the gas controls.

109A_5

If you suspect bad connections in the path to the Hot Surface Igniter I'd measure the Voltage as close to the Hot Surface Igniter as possible when it is in use. Since you expect the current draw to be in the range of 3.3-3.6 Amps I would expect the Voltage measured to be close to the present building's Voltage minus the Voltage across the gas valve controlled by the current. If there is a wiring diagram on the back or inside the unit it may help. If the Voltage is low check for loose or dilapidated connections in the path.

Increased circuit resistance lowers the current. Voltage drops elsewhere in the circuit indicates extra circuit resistance resulting in the normal full Voltage not getting to the Hot Surface Igniter, lowering the current.

If the gas control in this case is actually bi-metal activated and not solenoid activated, I would expect the supplemental resistor modification may work if nothing else is wrong with the circuit.

Crispy

Thanks all. Follow-up…. The "bad" broiler igniter pulls 2.9A, measures 122 ohms cold and sometimes pulls open the gas valve. It is a Java product and states on the heat shield, "3.0-3.7A at 116VAC". The new one is a CoorsTek product and pulls 3.4A installed. It measured 66 ohms cold. They look identical in shape and size, with silicon carbide heat elements mounted in ceramic holders. The new igniter spec sheet says "Steady State Current 3.2-3.7A at 116VAC". It lights the broiler in about 30 seconds. While these two igniters appear to be identical in looks and materials, the new one has slightly different specs. I took the opportunity to measure the bake igniter which has been replaced by me, probably with a $22 unit. It is slow to open the gas valve and pulls 2.9A. I am going to replace it. I will look into if I can find a less expensive unit with a higher amperage spec but I may end up paying the $176.75 for the one that works.

Having spent the last three years of my life growing silicon carbide crystals for use as semi-conductor wafers for Power Electronics device chips, I can tell you there is a lot that can go wrong. I don't know if this is simply a quality issue or if I truly can find different spec'ed units. Hope this helps someone with HSI woes. Thanks, C.

109A_5

It sound like there is a normal dilapidation with use and/or age. There may be production variances and the units depending on their actual properties go to different markets.

Personally I would not pay $176.75, that seems very excessive. I'd come up with another method that was not quite as finicky if needed but still retains the safety features.

Kind of sound like 120 VAC - 116 VAC = 4 VAC, so I would expect the heater that heats the bi-metal works at about 4 VAC at 3.0 - 3.7 Amps, plenty of heat. If the current is lower the heater does not make enough heat to activate the gas valve.

ratio

I had a similar problem with my GE oven. The ignitors will slowly fail (occasional failure to ignite, becoming more and more common). Changing the ignitor always fixed it, but sometimes I would wait too long and the replacement wouldn't get here in time for a warm dinner one night. I found that unplugging & plugging the ignitor back in a few times would just about restart the timer.

That, & I have a cold spare now, too. SWMBO was not pleased that I was unprepared for a known problem.

Crispy

I found some good information on Google AI. First it told me my Garland RCS30-IR oven didn't have a hot surface igniter. After I corrected that, the bot was very apologetic. It then went on to suggest using silicon nitride which is more robust with stronger mechanical properties at temperature. The problem is silicon nitride has lower resistance. It looks like it may be worth looking at. Some units have specs that overlap with SiC.

EBEBRATT-Ed

Who knows what the quality control of CHINA made parts is. Sounds like your on the right track

pecmsg

with the cost of those igniters I’m glad I still have a pilot light.