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Reply With Quotesounds like the pilot jet is dirty
Pilot light Gday everyone. I have a problem with my pilot light on my gas hot water unit. It wont stay on. I can ignite the pilot light easily and then turn the temp up so it starts heating. It will heat to the proper temp and then cut off, which is all good. But i think the pilot light may be blowing out when the thermostat cuts the main gas. Having said that, i have tried turning the thermastat up and then straight of to see if the pilot stays on and it did about 8-9 out of ten times, so this may not be the problem. But if the pilot stays on, and i leave it for about half and hour it will go out by itself. Now i have replaced the thermocouple and that didnt fix the problem. Any other ideas? small blockage in the pilot light gas line/jet. It goes out even when there is no wind so i can eliminate that cause. Can the intensity of the pilot flame be turned up/down? Thansk in advance. pete
sounds like the pilot jet is dirty
I had a similar problem with the unit going out - at least until I discovered the lawnmower guy used a backpack blower.
I reckon Bob's right in this case, you might also check to see if anyone turned the gas down at the meter, bored kids do dumb things at times.
Could be your new thermocouple, was it doing the same with the old one?
Is the thermo close enough to the flame?
Could be the control valve itself although rare.
Hen
Had a similar problem a while back, replaced the thermocouple to no avail.
The gas bloke that came out put the old thermocouple back in (said the universal type I'd bought wasn't as good) and cleaned out the pilot jet with a bit of fine wire. He said even a cobweb across it can cause problems.
Cheers............Sean
OK. So my pilot light is still going out. I have replaced the thermo couple, cleaned the pilot light jet, even had the gas supplier guy out to check if the gas pressure was sufficient...it was. So now im buggered if i have any more ideas (appart from getting a heating specialist but im tight and broke). The unit is only 2.5 years old. Any more ideas guys?
Did he check the pressure at the heater with a water gauge, another problem that can cause this is the diaphram at the meter deteriotates over time and the pressure drops with demand to a point where as the main burners light up there isn't enough gas to substain the pilot light as well, this is the responsibility of your gas supplier, ring them up and get it checked they should do it freeOriginally Posted by mako
Ashore
The trouble with life is there's no background music.
My gas supplier sent s guy around to check pressure but he said it was fine. Do'nt know what he checked though.
99% chance that the pilot jet is dirty if you have access to some cleaning drills (anyone with a oxy set will have them) run the appropriate size through the jet the blow the out
Clean the spud as others have suggested. If it is two years old call the supplier and tell him to come fix it.
Pete
Pete may contain traces of nuts................
i was just watching the main burner heat the tank and after about 3-4min there seemed to be water dropping onto the burner unit thingy and sizzling as it burnt it off. It would have 1 drop every 10 seconds or so. Does this mean there is a hole in the tank? Im thinking maybe after the main flame has finished it might still drip and splash onto the pilot light, putting it out. I really hope the tanks not stuffed !
Are you sure the water dripping is not condensation as the unit heats up?
Jack
yeah... probably. that would make sense.
If the tank is leaking and the water causes the main burner to go out the the flame out cut off will shut down the pilot light as well, seems very likely you need to replace the unit, I would be calling a plumber and get it sorted once and forall
Water dripping , sounds like the tank is leaking and only 2 & 1/2 years old, usually they last a lot longer than that, is it still under waranty and are all the fittings to the tank tight, make sure one of these isn't loose and leaking :confused:
Ashore
The trouble with life is there's no background music.
Old thread, but I have exactly the same problem. Changed the thermocouple with no luck. Took the jet and pipe out and blew them out with compressed air. I wanted to clean the jet with an oxy cleaning drill but the they were all too big. It seemed to have quite a good flow of compressed air though. Does anyone know how many mv a thermocouple should give, or are they all different?
Tools
I wouldn't say old but ancient.
Try thisThermocouple Reference Table
10-15mv is enough to keep the valve energised. you need to physically scrub the walls of the pilot spud using fractional drill bits. If there is incomoplete combustion there will be a carbon build up, which will effect flame performance, hence more carbon build up, i would do the same to the main flame jet spud..
ultimately this is probably as much as you can do, next stop would be product manufacturers.
I have about 15mv from the thermocouple, so that wouldn't then appear to be the problem. I don't know what I could use to scrub the spud with ( I assume you mean the jet) as it is so tiny. Maybe I should just replace the jet so I know all is good.
Tools
We actually use very small hand (finger) held (very similar to accupuncture needles) drill bits. They come as a box, quite expensive.
Brisrab, I assume you are a gas fitter? I bought a new jet and put it in and I couldn't tell any difference with the flame. If I play with the thermostat it will cycle on and off and the pilot stays lit. I did that probably 30 times yestaerday and it stayed lit every time. I left it on and it heated one cycle and when I went to check it an hour later the pilot was out again! So I don't think it is the jet or the thermocouple. Gas valve maybe? Do these ever fail? I assume that when you refer to the spud you mean the jet?
Tools
As i said b4 check the pressure at the heater , diaphragm at the front deter deteriorates over time and the pressure drops too far under load ,( load being not only from water heater but what ever else you use gas for )
When you changed the jet did you adjust the air to the jet as well to get the best flame ?
Ashore
The trouble with life is there's no background music.
I haven't checked the pressure, but the ducted heater is close by and I haven't had any issues with that. If I do check the pressure, how do I know what it should be anyway?
When I did the jet I did have a play with the pilot adjustment on the side of the gas valve but it didn't make any difference at all. The flame is burning blue and constant so I suspect it is ok.\\Tools
sorry about delay but...
The unit will be required to run a specific working pressure. LPG is generally around 2.75 kpa and Natural gas approx 1.13kpa. The pressure specific to the HWS will be on the units rating plate.. Generally a nice firm blue flame with no yellow tipping is ideal burning. indicating good gas pressure.
I am thinking that if the pilot flame does actually stay alight but goes out after a long period of time it will be a heater specific problem, especially if the pilot relights as soon as you fire it up.There a a few could-be's but I would suggest to contact your local experienced agent.
Thanks for the suggestions guys. I re-installed the old thermocouple and played with the location in the flame for a while but no joy. I decided to get a new gas valve which I did ($140.00), put it in and it works well now. The old valve must have just got a bit weak or tired. When I get time I will perform an autopsy on the old one to see where it failed.
Tools
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