Dishwasher
E19
The E19 error code on a Bosch dishwasher points to a fault with the flow heater or its temperature sensing system — it’s a moderately serious fault that will stop your machine from completing a wash cycle until it’s resolved.
What does this error mean?
E19 indicates that the dishwasher’s flow heater (also called an instantaneous or continuous flow heater) is not heating the water correctly, or the control board is not receiving the expected signal from the heater’s integrated temperature sensor (NTC sensor). Bosch uses this code specifically on models fitted with a flow-through heating element rather than a traditional tank heater. Because the machine cannot verify water is reaching the correct temperature, it cuts the cycle short as a safety measure.
Est. repair cost
£60–£200 professional repair depending on part (NTC sensor vs full flow heater); £20–£55 DIY part cost if you’re replacing the NTC sensor yourself
🔍 Likely causes
🛠️ Step-by-step fix
Reset the machine first: switch the dishwasher off at the wall, wait 5 minutes, then switch it back on and run a short cycle. A one-off control board glitch can trigger E19 and a hard reset clears it.
Clean the filters thoroughly: remove the coarse and fine filters at the bottom of the tub, rinse them under the tap, and check that the drain area is clear. A blocked filter forces the pump to work harder and can cause heat-related faults.
Run a hot descaling cycle: if you live in a hard-water area (check your water supplier’s website), use a dishwasher descaler product such as Finish Dishwasher Cleaner. Limescale on the flow heater is a very common cause of E19 in UK homes.
Check the water supply: ensure the inlet tap (usually under the kitchen sink) is fully open and water pressure is normal. Low water flow through the heater can trigger an overheat cut-out.
Inspect the wiring to the heater (only if you are confident working around unplugged appliances): pull the dishwasher out, unplug it from the mains, remove the kickplate, and check that the connectors on the flow heater wiring loom are fully seated and undamaged. Do not open any sealed electrical components.
If none of the above resolves E19, stop here — the flow heater or NTC sensor will need to be tested with a multimeter and likely replaced. This is a job for a qualified appliance engineer.
📞 When to call a professional
If the E19 error returns after a reset, descale, and filter clean, book a qualified appliance engineer — at this point the flow heater assembly or NTC sensor almost certainly needs replacing, which requires safely dismantling internal components. When you call, tell them: ‘My Bosch dishwasher is showing error code E19 — I believe it’s a flow heater or temperature sensor fault.’ This saves diagnostic time and may reduce your call-out cost.
⚖️ Repair or replace?
A flow heater replacement on a Bosch dishwasher typically costs £100–£200 including parts and labour in the UK; an NTC sensor alone is cheaper at £60–£120 all-in. If your machine is under 5 years old, repair is almost always worth it — Bosch dishwashers are built to last 10–15 years. If it’s over 8–10 years old and has had previous faults, compare the repair quote against a new mid-range Bosch (around £400–£600) and factor in the engineer’s assessment of the machine’s overall condition.