My pool heater is acting up this year. Once the pilot is lit, it stays
lit. The thermostat works, in that I can hear it click as it is
rotated past a certain point, and my meter shows that it is opening and
closing with the click. The vast majority of the time, rotating the
thermostat to the point of calling for heat, does NOT fire the burner.
If I jumper the TH terminals, and get the burner started, then the
thermostat usually takes over and lets the burner cycle off and on.
But if the thermostat quits firing the burner, I have to jumper it
again. Since the thermostat is wired to the pressure safety switch, I
was thinking that maybe the pressure safety switch was going bad, but
that is just a guess. Before I start replacing parts, I thought I's
post here.

Can someone point me in the right direction? I'd appreciate any
help/info.

Tim