Hayward H100id1 heater not starting reliably

[MRosauer]

I have a Hayward H100id1 natural gas heater for a 16'x24' above ground pool.
The gas does not light reliably. I put a voltmeter on the wires going to the gas valve. The voltage was 120VAC which was correct per the electrical diagram. I assumed that the valve was bad so I replaced it. $222. The heater fired up after that. Now, week later, it is igniting intermittantly. The fan starts, I can hear the ignitor sparking, but no ignition. The voltage is reading 120VAC. Anyone have this type of failure.

Background on heater.
Installed 5/2006. Had to have a service tech out just after installation as it would fire up but stop almost immediately. There was too much air entering the combustion chamber and the flame would blow out. Caulk over some of the holes fixed that problem.
2 years later the diverter inside the heat exchanger broke loose. This allowed the water to flow through the main pipe but did not force the water to flow through the heat exchanger. This casued boiling in the heat exchanger which made a banging sound like rocks were passing through the heater. The brazed connection points of this diverter were very small and vibrations of the diverter eventually caused them to fail. Replacement core $450. I repaired the core instead. I did not braze it, but a radiator shop may be able to fix it if you have this type of failure or a leak or crack. Still makes a few "bangs" when the heater first ignites and then goes quite. This year the gas is not igniting.

 

[danpik]

On the board there is a connection that a Molex plug with 4 wires on it that pugs into the board. Check the solder connections with a magnifying lens. They have a tendency to crack and need to be re-soldered

 

[ps0303]

On these units a visual inspection of the ingniter is usually required. It might sound like a good spark but it at times isn't strong enough or the gap is off. The other thing is can you smell gas while it's sparking?

To check the igniter you have to pull the front panel off and then hold in the panel interrupter switch making the system think the front panel is on. Carefully you should be able to then inspect the igniter while sparking. Be very careful because if it does decide to light this time you could get flame blow back at you. It happens from time to time. You might even have to pull the igniter and clean it with some emery cloth. Just make sure not to bend the rods. Just like a spark plug, they are gaped. If that gap is too much or not enough you have issues like this.

Here is a manual and diagram of the circuitry if you don't have it.

https://www.parts4heating.com/v/vspfile ... Ground.pdf

 

[MRosauer]

On the board there is a connection that a Molex plug with 4 wires on it that pugs into the board. Check the solder connections with a magnifying lens. They have a tendency to crack and need to be re-soldered

Thanks danpik. I will check that as soon as I fix the leak that just appeared in the heat exchanger. Yikes!!!
The hole is where I can see it. Since the core is now useless, I bent the fins apart, cleaned the area, fluxed like crazy and soldered it. Held pressure now I'll see if it can take the heat. Another weak spot will probably break open. I also discovered the internal diverter broke loose again. I will have to decide: whole new unit or just a new heat exchanger.

 

[MRosauer]

On these units a visual inspection of the ingniter is usually required. It might sound like a good spark but it at times isn't strong enough or the gap is off. The other thing is can you smell gas while it's sparking?...

I had shut the gas off, pulled out the igniter, positioned it where I could see the electrodes, and started the heat cycle. There was a nice spark jumping between the electrodes with a meanicing buzz. I could hear that buzz when everything was reassembled and the heat cycle was started. I did not smell gas while the igniter was running.
Thanks for the input.

 

[danpik]

I had shut the gas off, pulled out the igniter, positioned it where I could see the electrodes, and started the heat cycle. There was a nice spark jumping between the electrodes with a meanicing buzz. I could hear that buzz when everything was reassembled and the heat cycle was started. I did not smell gas while the igniter was running.
Thanks for the input.

If you had the gas shut off you should not have smelled any. When the gas valve opens on these there is a fairly good audible click.

 

[ps0303]

On the board there is a connection that a Molex plug with 4 wires on it that pugs into the board. Check the solder connections with a magnifying lens. They have a tendency to crack and need to be re-soldered

Thanks danpik. I will check that as soon as I fix the leak that just appeared in the heat exchanger. Yikes!!!
The hole is where I can see it. Since the core is now useless, I bent the fins apart, cleaned the area, fluxed like crazy and soldered it. Held pressure now I'll see if it can take the heat. Another weak spot will probably break open. I also discovered the internal diverter broke loose again. I will have to decide: whole new unit or just a new heat exchanger.

Yeah probably time for a new heater.

 

[ps0303]

On these units a visual inspection of the ingniter is usually required. It might sound like a good spark but it at times isn't strong enough or the gap is off. The other thing is can you smell gas while it's sparking?...

I had shut the gas off, pulled out the igniter, positioned it where I could see the electrodes, and started the heat cycle. There was a nice spark jumping between the electrodes with a meanicing buzz. I could hear that buzz when everything was reassembled and the heat cycle was started. I did not smell gas while the igniter was running.
Thanks for the input.

Good thing you shut the gas off or you could have had an explosion.