Pool heater not heating? We'll tell you why.

Pool heater not heating? We'll tell you why.

Nine times out of ten in North County, a gas heater that won't fire isn't the heater. It's flow. A dirty filter, a clogged pump basket, or a cell throwing a low-flow warning drops the water below what the pressure switch wants to see, and the heater sits there doing nothing — sometimes with no code at all. So the first thing we check is the filter gauge and pump prime, because if that's it, it's a maintenance fix and you're heating tonight.

If flow is fine, we go through the heater the way the manufacturer's service manual does. Gas supply and pressure at the valve. Ignition: is the igniter glowing, is the flame lighting, is the flame sensor seeing it — a flame sensor coated with the white residue you get near the coast is a common one on Raypak and Pentair units. Thermistors and the high-limit switches, which fail from scale on hard-water pools. The bypass valve and the heat exchanger, where calcium builds on Vallecitos water until the unit short-cycles, or where a leak shows as water under the cabinet. On heat pumps, refrigerant pressure, fan, and the ambient cutoff, which stops a heat pump cold on a 50-degree January morning and isn't a fault at all.

You get it in writing the same day: what we found, what's wrong, and whether it's the kind of thing that's fine to run for another season or the kind of thing that isn't. We don't guess, and we don't tell you a heater is dead to move on to the next stop.

If it needs more than a diagnosis

Work that needs a C-53 goes to our referral partner: Pool-Clinic Inc., a licensed C-53 swimming pool contractor, CSLB #1122305. You contract with them directly and pay them directly. We take nothing. Our write-up goes with you, so you know exactly what you're being quoted for.