Hayward Millivolt H200 Heater

[byeloe]

Hi

I was having trouble getting my heater to fire, so I watched some videos, changed the pilot assembly, tested all the switches and cleaned all the contacts.

Great now it fires, but then the pilot goes out. Seems like the initial combustion is blowing it out.

Any suggestions?

Thanks

 

[Bama Rambler]

Did you clean the burner tube completely? A lot of times spiders will build in them and when the unit fires it'll blow back blowing the pilot out.

Maybe our resident gas expert Paul (PS0303) will see this and comment.

 

[byeloe]

I checked the tubes and blew them out with my air compressor. Now getting 500+ millivolts, but it won't fire. Thought I had it firing pretty well yesterday. The pilot still goes out when I jumpstart it. So two issues to fix now

 

[Bama Rambler]

If you don't get any help in a little while, PM Paul and see if he'll take a look at this thread.

 

[ps0303]

Propane or natural gas?

So you light the pilot and it stays lit with no issues. But when you turn the heater on the pilot goes out? I'm guessing that the unit stays lit and working until you turn it off. Then you are left with no pilot for the next time you go to use the heater. Can you take a meter and test the millivolt reading to see what it is at when it's in standby mode? You should be 450+ for it to operate correctly.

 

[byeloe]

It's natural gas. I am getting 500ish mv with the tstat below water temp. When I turn up past where it clicks, mv drops to 360ish, but heater doesn't fire. I can jumpstart it and it will go, but it will not refire on it's own.

 

[byeloe]

And then the odd time it fires by itself, like just a few minutes ago

 

[ps0303]

It shouldn't drop that low when you fire it up. Is water flow good?

 

[byeloe]

Where do I check that? At the pool jets? Then yes. If I jumpstart the heater, I get 240mv across THPP and PP but only 95 Across TP and PP

 

[ps0303]

When you have a drop in power like this then you have an item that is shorting the power. My first stop to check on these units is the on/off switch. Disconnect the two wires to it and use a jumper wire. Keep in mind it will fire up right away if this is the issue. You can also use your meter to check the voltage along all of the safeties and that too can tell you where you have an issue.

 

[byeloe]

thanks


I tried jumping the toggle switch but the heater did not fire. When I turn temp down until heater shuts off, the THPP to PP reading takes awhile to build back up to the 500ish range, but the heater will refire at that point(at least it just did it a couple of times). Back when the heater was working well, it used to turn on and off(a lot quicker) by moving the thermostat past the click

 

[ps0303]

Is it a nice blue flame?

 

[byeloe]

Are you referring to the pilot? Very difficult to see on this unit in the daylight

 

[ps0303]

Yes the pilot. It should be a nice blue constant flame.

 

[byeloe]

I will try to have a look, if I can't see it well, I will look again tonight and report back

thanks

 

[byeloe]

Just checked and yes the pilot is solid blue flame.

 

[ps0303]

I would start checking with a meter to see if all of your safeties are working ok. Sounds like one or more of them are drawing down the power when you turn it on.

 

[byeloe]

I would start checking with a meter to see if all of your safeties are working ok. Sounds like one or more of them are drawing down the power when you turn it on.

Thanks, can you explain how to do that?

 

[byeloe]

how do I tell if they are working?

 

[byeloe]

got it working, I was missing the two switches covered by rubber boots, beside the water intakes