Cal Spas DR Warning — Dry Heater Protection Fix

What Does This Error Mean?

DR (dry) is a serious code — the heater detected it's running without water (dry firing).
Continued dry firing burns out the heating element within minutes.
Power off at the breaker immediately.
Check water level (must be above the skimmer intake), filter (clogs cause flow loss), and valves.
Once water is flowing, the heater can run safely.
If DR returns, the heater may already be damaged.

Affected Models

Cal Spas Patio Series
Cal Spas Hawaii
Cal Spas Genesis
Cal Spas Atlantic Series

Common Causes

Water level below skimmer intake (most common)
Filter completely clogged blocking flow
Closed valve preventing water reaching heater
Air lock in pump after water change
Pump failed — no flow regardless of water level

How to Fix It

Power off at the breaker immediately.

Don't run the heater dry — every minute it runs without water destroys the element more.
Switch the spa breaker off.
Wait at least 5 minutes before doing anything else — the heater needs to cool.
Check water level.

Open the cover.
Water should be above the skimmer intake (the rectangular slot on the spa wall) but below the headrests.
If low, fill with a hose.
Keep filling until water is at the proper level — about 2-3 inches above the skimmer.
Pull and inspect the filter.

Open the filter compartment.
Pull the cartridge out.
Look at it — heavily clogged filters block flow even with water at the right level.
Rinse thoroughly or replace.
Reinstall.
Confirm valves are open.

Walk around to the equipment area.
All valves should be in OPEN position.
Closed valves prevent water from reaching the heater regardless of water level.
Make sure none are partly closed — closed enough to restrict flow but not enough to be obvious.
Restart and watch carefully.

Restore power at the breaker.
Watch the spa for 5-10 minutes.
Pump should prime, water should flow, and the heater should engage.
If DR returns within minutes, the heater is likely damaged from previous dry firing — service required.
Heater replacement: 200–500 USD parts plus labor.

Frequently Asked Questions

Can a heater be saved after DR?

Sometimes, if caught quickly.
If DR triggered after a few seconds of dry fire, the element may be undamaged.
If it ran dry for 30+ seconds, the element is likely warped or burned out.
The service tech will test continuity and inspect for visible damage to determine.

How can I prevent DR?

Maintain water level — check weekly during use.
Clean filters monthly.
Don't run the spa during water changes — power off until refill is complete.
Bleed pumps after refilling to clear air locks.
These habits prevent 95% of DR events.