Pool Heater

jholling

New member
May 2, 2007
3
Please Help! I have a hayward H400 Milivolt heater. 4 years old. Pilot light comes on but the unit will not fire??? Spider webs?? How hard is it to remove the burners and clean the unit?? Thanks!!
 

krcossin

Platinum Supporter
LifeTime Supporter
May 14, 2007
113
Detroit Burbs
I don't have your heater, but I also experienced no fire condition. I had to disassemble the gas fitting after the shut off valve/prior to the heater. Open it up to purge the line, fired right up.
 

Denali

Well-known member
May 1, 2008
70
jholling said:
Please Help! I have a hayward H400 Milivolt heater. 4 years old. Pilot light comes on but the unit will not fire??? Spider webs?? How hard is it to remove the burners and clean the unit?? Thanks!!
It could be spider webs but it could also be any of the safety devices (pressure switch, hi limit) holding the burners off.

Removing the burners is involved by not difficult. I pull my burners every year to clear spider webs. Takes about an hour.
 

jholling

New member
May 2, 2007
3
Thanks for all of the help! I cleaned out the orifices and let the gas line purge, it has about a 80' run and has been shut off since october. Fired right up!!!
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,863
Sebring, Florida
krcossin & Denali,

Please move to the head of the class and pick up your gold stars!! :lol: :lol: :lol: Great advice!
 

Titanium

LifeTime Supporter
Jun 26, 2007
441
SF Bay Area
I have an older (25 years) Laars gas heater, but I have never cleaned any orifices or purged the line. And the heater typically goes most of the winter without being turned on.

What is involved in orifice cleaning and line purging. The previous poster mentioned removing the burners. I think I can do this, but then how do you get the gas flowing through the gas valve?

Titanium
 

Denali

Well-known member
May 1, 2008
70
Titanium said:
I have an older (25 years) Laars gas heater, but I have never cleaned any orifices or purged the line. And the heater typically goes most of the winter without being turned on.

What is involved in orifice cleaning and line purging. The previous poster mentioned removing the burners. I think I can do this, but then how do you get the gas flowing through the gas valve?

Titanium

If you decide to pull the burners you can purge the line at the same time. To get the burners out you need to undo the union in the gas line. This is either in the heater to the left of the gas valve or just outside the heater.

On the Laars there are some screws holding the burner assembly in place. If you're lucky someone has already removed them and not bothered to put them back. They can be a pain to get out.

Once the burner assembly is out, you remove each burner. They pull right out. You will see a burner orifice for each burner. They thread out. Once out you can see if there are webs in there. Clean them out and reinstall.

For purging you don't need it flowing through the gas valve. Purging out of the union you have open is usually fine.