Hayward H400 Natural Gas Heater - Average Lifespan in South Florida


New member
Jul 4, 2020
West Palm Beach, FL
I have a Hayward H400 natural gas heater that is the original heater from when the pool was constructed in late 2004. I'm in South Florida and am wondering what the typical useful lifespan would be of this unit under normal operating conditions, because I have a number of what I perceive to be smaller issues that to together may suggest that it's time to replace the unit.

The smaller issues are:
- the heater is not starting and I'm getting the "IF" code for ignition failure. I changed modes from spa back to pool, waited for the valves to turn plus a few minutes more, and then changed back to spa mode. Once back in spa mode I attempted to turn on the heater and it behaved as it is supposed to when there is an ignition failure - 3 cycles of ignition attempts and then posted the IF code again. I've confirmed gas flow, can smell it, and can hear the "whomp" during attempted ignition, suggesting an igniter or maybe a temperature limiter issue.

- the water pressure relief valve on the side of the unit is leaking water during normal pool pump operation and the pressure on the guage is in the normal operating range. More than just drips but not quite a "flow," enough to cause small puddling/ponding of water in the grass by the unit.

Any input or suggestions would be appreciated. I'd rather not replace the unit if I can avoid by making the small repairs, as I only plan to be in my house another 2-3 years at most. However, I still want to enjoy my spa while I'm still here, and the spa is the only thing the heater is used for. I've never needed the heater for the pool as I'm in South Florida and the pool water is almost always perfect, if not a tad on the warm side from the direct sunlight.



TFP Expert
LifeTime Supporter
May 3, 2007
Pleasanton, CA
I have had mine since 2005 without any issues.

If you are hearing the ignition, then IF is usually due to spider webs in venturi injectors so not all of them light properly. Unscrew them and clean them out.

The water pressure relief valve can be replaced.