Dishwasher not heating? Why the water's cold and dishes stay wet
If your dishes come out cool and greasy, or the plastics are still soaking at the end, the dishwasher probably isn't heating the water. We attended 200 dishwasher jobs for this fault in the last 12 months. Here's what's doing the heating and what tends to go.
How a dishwasher heats
Most machines no longer have a visible element in the base. The water is heated as it's pumped round, by a flow-through heater built into the circulation pump, or on a lot of Bosch and Neff machines by the heat pump that also handles the drying. Worth knowing, because it means "not heating" often points at the same assembly whether the complaint is cold water or wet dishes.
Rule these out first
A cold or eco cycle that runs cooler can look like a heating fault, so check the programme before anything else. And poor drying on its own, with the water clearly hot, is often just low rinse aid rather than a heating problem, so top up the rinse aid and see if it clears.
When it's a fault
If it's genuinely not heating, the flow-through heater or heat pump assembly has usually failed, and it's one of the parts we replace on dishwashers. A faulty thermostat, or the sensor that tells the board the water temperature, can do it too. They need testing to tell apart.
What a repair costs
Going on our own jobs, customers typically paid £203 to £302 in total for this repair, including parts and VAT (from 113 repairs). You'll have a fixed price before any work starts.
Book a dishwasher repair
If the programme's right and the rinse aid's topped up and it's still not heating, book a dishwasher repair or find your local dishwasher engineer.
Frequently asked questions
Why is my dishwasher not heating the water?
On most machines the water's heated by a flow-through heater in the circulation pump, or a heat pump. When it genuinely isn't heating, that assembly, or a thermostat or temperature sensor, has usually failed.
Why are my dishes still wet at the end?
Either poor drying from low rinse aid, which is an easy fix, or a real heating fault so the final hot rinse never happens. Top up the rinse aid first to rule it out.
Does a dishwasher have a heating element?
Older ones had a visible element in the base. Most modern machines heat the water as it circulates, through the pump or a heat pump, so there's no separate element to see.
How much does it cost to fix?
Customers typically paid £203 to £302 in total for this fault, including parts and VAT (from 113 repairs). We confirm a fixed price before any work starts.
What our engineers found on 200 jobs
The figures below come from NAC's own repair records: 200 dishwasher jobs our engineers attended for this fault, what they found, what fixed it and what it typically cost.
When a dishwasher stops heating the water, the cause most often turns out to be a failed heat pump. On many machines the heater is built into the pump that pushes water round the spray arms, so when its heating part fails the dishwasher can still fill, wash and drain, but the water stays cold and the dishes come out poorly cleaned and wet. The next most common cause is a failed heating element, the separate heater found in other machines. Some dishwashers show an error code or a flashing warning light when this happens.
To find the fault, an engineer checks the heater with a meter to see whether it has broken inside, and may also check that power is reaching it. If the heater has failed, the heat pump or heating element is replaced. This part often has to be ordered for your model and fitted at a second visit. Once it is in, the engineer runs the dishwasher on a hot wash to make sure the water heats properly, then checks that it fills, drains and washes as it should with no leaks.
Written by our engineers from these jobs.
- Jobs attended
- 200
- Confirmed repairs
- 115
- This is not a success rate. Jobs inside their 60-day window, jobs still being classified, jobs held for review and visits that didn't end in a repair aren't counted.
- Fixed at the first appointment
- 4%
- about 1 in 30 of our repairs
- Typical total paid by customers
- £203 to £302
- including parts and VAT, from 113 repairs
What's usually behind it
The causes our engineers found and fixed, as a share of our 115 confirmed repairs for this fault.
-
Failed heat pump: about half of our repairs, from 61 jobs.
53% -
Failed heating element: about 3 in 10 of our repairs, from 34 jobs.
30%
We only list causes with enough repairs behind them, so the shares won't add up to 100%.
Error codes we see with this fault
- Bosch E09: Heating fault, usually in the heat pump circuit.
- Bosch E23: Drain pump fault: the appliance is not draining.
- Neff E09: Heating fault: heater open circuit.
- Siemens E09: Heating fault in the heat pump or heater circuit.
By brand
Brands with enough repairs of their own for this fault to show separately.
Bosch dishwasher not heating
61 jobs, 36 confirmed repairs. Customers typically paid £246 to £302 (from 36 repairs). 0% fixed at the first appointment.
This is not a success rate. Jobs inside their 60-day window, jobs still being classified, jobs held for review and visits that didn't end in a repair aren't counted.
- Failed heat pump 94%about 9 in 10 of repairs, from 34 jobs
Why the first-appointment figure differs by brand. Our engineers carry common parts on the van, so those repairs can be finished at the first appointment. Other parts have to be ordered in, and fitting them takes a second visit.
About the price. £203 to £302 is the typical total paid by customers, including parts and VAT: the middle half of what customers paid on 113 of these repairs. Repairs paid for by manufacturers and insurers aren't counted, because that work is charged at contract rates. It's a guide, not a quote. Your engineer confirms a fixed price before any work starts.
- Dishwasher repair
- Dishwashers
- Not heating
- Heat pump
- Drying
Rather leave it to us?
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