Replace the baptistry water heater. Plumber from Lexington coming.
Next steps
Plumber visit: swap the heater, check fittings and pump
Micheal
Waiting
Replacing the baptistry water heater. The baptistry has an electric circulation heater plus a separate circulation pump, both made by Little Giant. A plumber from Lexington is coming; these photos are organized so he can plan ahead.
Equipment at a glance
Old heater (installed): Little Giant electric circulation water heater, Model 6HHL, 6 kW, 240V single-phase, 60 gal/hr recovery at 40°F rise. A thermostat control box with a dial sits on top. The serial number is partly worn off (starts '996').
Replacement heater on hand: Little Giant Model 6HHL, 6 kW, 240V. Same model and rating as the old one, so it should be a direct swap. Shipping label: sent 9/23/25 by Memphis Pool Supply ((901) 383-6077, 'Ronnie') to First Christian Church, Murfreesboro, AR; 14 lb. Handwritten '9-25-25 Memphis Tenn.' It looks like the heater body only. Check whether the thermostat control box on top comes with it or moves over from the old unit.
Circulation pump (separate): Little Giant Pump Co., Model 4-MD, Cat. No. 582003, 115V, 2.4A, 1/12 HP, thermally protected. It plugs into a regular outlet next to the heater. The heater must never run without the pump running and the baptistry full.
Plumbing: older galvanized steel nipples, elbows and tees at the heater with brass gate valves (blue and red handles). The fill/supply lines are 3/4″ CPVC with shut-off valves.
Electrical: subpanel breakers labeled 'Baptistry Heater 240V' (2-pole) and 'Flow Meter / Filter Pump'. There's a disconnect box at the heater. The manual says the heater must be on a GFCI-protected breaker and installed by a licensed electrician.
1. Replacement heater on hand
Nameplate - Little Giant 6HHL 6kW 240VShipping label - Memphis Pool Supply 9-23-25Handwritten 9-25-25 Memphis TennInlet-outlet fitting
Manual covers the 6 kW and 11.5 kW Little Giant electric circulation heater and pump.
Thermostat: #4 on the dial = 45°F, maximum 105°F at #10. Hi-limit trips at 118°F.
Never run the heater dry: fill the baptistry first, and the pump must run whenever the heater is on.
No chlorine, bleach or acidic chemicals: they cause rust and void the warranty. Little Giant: 1-800-231-6035.
3. Existing heater and pump
Old heater - Little Giant 6HHL 6kW 240V with thermostatOld heater top - caution label and valveOld heater and circulation pump in placePump nameplate - Little Giant 4-MD 115V 1-12HP
4. Plumbing
Galvanized pipe and gate valve below heaterBrass union and valve on lineLines under baptistryCPVC supply lines with valvesCPVC lines along baptistry - 1CPVC lines along baptistry - 2
The old galvanized nipples and fittings at the heater are rusty. Worth replacing them with new unions while the heater is out.
Look at the wood in the first plumbing photo: there's dark staining above the pipes, possibly from an old leak.
5. Electrical
Breaker panel - Baptistry Heater 240V and Filter PumpDisconnect box at heaterOutlet the pump plugs into
Unlisted working page (not in the site menu). Updated 2026-10-14.
