DR on a hot tub:
the heater is dry.

What DR means

DR, DRY or DY means the control board believes there is no water inside the heater assembly. It disables the heater immediately, and it is right to. An element energised with no water around it burns out in a very short time, and it is one of the more expensive parts on the tub.

Note the wording though: the board believes the heater is dry. Sometimes it is right and sometimes the detection has failed. Both are worth knowing about before anyone resets anything.

Check, in this order

• Water level. The single most common cause. If the level has dropped below the skimmer intake, the pump is drawing air and the heater genuinely may be running empty. Top it to the middle of the skimmer opening.
• The filter. A filter packed solid can starve the heater as effectively as an empty tub. Pull it out and try again with no filter in.
• Air lock. Very common right after a refill. The pump sounds like it is running and is moving nothing. With the power off, loosening a pump union slightly until air escapes and water appears usually clears it. If your pack shows PRR or PROG after a refill, that is priming mode attempting the same thing.
• Then reset once. Once. Not repeatedly.

Why repeated resets are the expensive mistake

Every reset asks the tub to energise a heater the board thinks is dry. If the board is correct, you are cooking an element that was fine two resets ago. This is the fault where impatience genuinely costs money, and it is why we would rather you called and described it than kept pressing a button.

When it is a real fault

• The circulation pump has failed and is not delivering water to the heater at all.
• A pressure or flow switch has failed, so the board never gets confirmation that water is present. Same family as a FLO error .
• The heater has already gone, in which case DR is the symptom of a job that has already happened.
• A leak has been draining the tub quietly, which is worth finding regardless of the code.

Where we stop

Electrical work on a spa circuit is licensed work in Michigan and Dr. Spa does not do it. We diagnose everything on the spa side of the disconnect. If your tub is also tripping its breaker, that is a different problem — see a hot tub tripping the breaker .

Related codes

FLO and FL1 , HL and HFL and a tub that will not heat overlap heavily with this one. The full error code index covers all twelve.