How to Replace a Spa Heater

There are two types of common spa heaters: electric and gas. An electric spa heater is powered by 110 or 220 volts. It is usually an in-line heater with a heating element in a metal or plastic housing attached on the discharge side of the pump. Gas spa heaters come in natural gas or propane models. A gas heater usually looks like a large metal box in the equipment area on the discharge side of the pump.

Difficulty: Moderate

Instructions

Things You'll Need:

• Pipe wrench
• Crescent wrench
• Box wrench
• Screwdriver

Replacing an Electric Spa Heater

1. Turn off the power and water to an electric heater at the circuit breaker panel. Turn off the water valve on each side of the heating unit.

2. Drain the spa if the ends of the pump-heater assembly have no valves. There is a drain fitting that's used to change the water periodically. Open the valve, and the water will flow out.

3. Disconnect the power line to the heater. In some cases, it is plugged into the spa control panel, so just unplug it. If it is hard-wired in, remove the wire connectors in the junction box on the heating unit.

4. Use a pipe wrench to remove the fittings that hold the heater in place. These are usually large, threaded unions on each end of the housing.

5. Install a new heating unit in the same manner as you removed the old one, making sure it has the same fittings and electric voltage requirements.

6. Re-fill the spa with water, making sure the drain line is closed, if it has been drained. If the spa was not drained, open the valves on each side of the heating unit to allow water to fill the unit.

7. Turn the power back on.

Replacing a Gas Spa Heater

8. Turn off the gas supply to the heater, and turn off the power at the electrical panel.

9. Disconnect the electrical power to the heater control panel by removing the wire nuts.

10. Disconnect the gas line to the heater with a crescent wrench.

11. Use a pipe wrench to disconnect the inlet and outlet lines to the heating unit; these are usually PVC pipe with threaded unions. If unions are not used, cut the lines with a hacksaw or pipe cutter.

12. Close the shutoff valves (if used) to eliminate siphoning. Water may siphon from the spa when the lines are removed.

13. Install a replacement heating unit in the same manner as you removed the old one, making sure the specifications and fittings are the same on both units. If union fittings were not used, use couplings and glue the fittings together.

14. Reconnect the gas supply line and electrical wiring to the heating unit.

15. Open the valves (if used) at each end of the equipment.

16. Turn on the electrical breaker.

17. Turn on the pump and heater.

Tips & Warnings

• Because a gas-heated spa is usually installed in ground and the heating unit is above ground, the spa should not have to be drained. A solar heater is another type of spa heater.
• Contact a licensed electrician if necessary. Use caution and proper safety procedures when working on either type unit. Check for leaks on either type of installation after you've replaced the heater. Water leaks are visible. Check gas or propane leaks by spraying soapy water on the fittings. Bubbles will appear if leaks are present. Tighten fittings until the leaks stop.