Bosch H01 Code: Water Taking Too Long to Heat

Quick Answer

The H01 code on a Bosch dishwasher is actually a 1-hour Delay Start setting, not a mechanical error. To fix it, simply press the Delay or minus button until the display returns to 00 or reset the machine by holding the Start button for three seconds.

H01 is a timeout, not a full failure. Your Bosch waited for water to hit the target temp and it just couldn't get there in time. Honestly, the most common fix I see is running the hot tap for 60 seconds before you start the cycle. That alone clears it the majority of the time. If it keeps coming back even with hot incoming water, the NTC sensor or flow-through heater needs testing.

BoschDishwasherSeverity: moderateDifficulty: intermediate85% DIY Success

Time to Fix

15–90 min

Difficulty

intermediate

Parts Cost

$15 – $160

Tools Needed

Digital multimeter with resistance (ohms) setting, Phillips #2 screwdriver

What Does the H01 Code Mean?

Here's the thing about H01 vs E09 - they're not the same problem. E09 means your heater's dead. H01 means the heater's working but the water just didn't warm up fast enough. Bosch builds in a heat-up timeout. If it doesn't hit the target temp in time - whether that's cold incoming water, a tired heater, or a drifting NTC sensor - it throws H01 and quits the cycle rather than running forever.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Accidental activation of the Delay Start timer85%

Stuck or tacky keypad button holding the contact closed10%

Control board software glitch requiring a hard reset5%

Symptoms You May Notice

H01 code shows up on the display partway through a wash cycle, usually 15-20 minutes in when the heater should've already hit target temp
Cycle stops cold during the main wash or sanitize phase and just won't continue
Dishes come out with food still stuck on them, or the sanitize indicator light never lights up at the end
The problem only shows up from November through March, then disappears in spring like nothing ever happened
Machine fills and starts normally, you can hear it running, then it stops mid-cycle and throws the code

Can you reset a Bosch dishwasher to clear the H01 code?

Press and hold the Start/Reset button for 3-5 seconds until the display clears or the drain pump kicks on briefly. That clears the H01 code. Before you restart, run the hot tap for 60 seconds first. Don't just hit start again or you'll probably get the same code immediately. Once you've flushed the line, start a Normal cycle and watch it through.

Tools Required for Diagnosis

Digital multimeter with resistance (ohms) settingPhillips #2 screwdriverFlathead screwdriverTowels or shop rags for water in the sumpFlashlight or headlamp

Service / Diagnostic Mode

With the door open, hold down two cycle buttons simultaneously, then press the Power button. Release all buttons when the display shows letters and numbers. Use the cycle buttons to navigate to stored error codes.

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

ComponentComponent Under Test

Expected Range10000–12000 ohms at 70F

ConditionIf Open (OL) or infinite, replace component.

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name	OEM Number	Estimated Price
NTC Temperature Sensor00165258 · $15–$30	00165258	$15 – $30
Flow-Through Heater Assembly00674541 · $85–$160	00674541	$85 – $160

Frequently Asked Questions

Is H01 the same as E09 on a Bosch dishwasher?

No, they're completely different problems. H01 is a timeout - the heater ran but couldn't get the water to temp fast enough. E09 means the heater's totally dead, no heat at all. Here's a quick way to tell: run the hot tap for 60 seconds and try again. If H01 disappears, your heater's fine and you just had cold incoming water. If you're seeing E09, that's a different story and you're looking at a heater replacement, usually $150-250 in parts.

Should I run the hot water tap before starting my Bosch dishwasher?

Yes, especially in bigger houses. If your water heater is more than 20 feet from the kitchen, there's a solid amount of cold water sitting in that supply line. Running the tap for 60 seconds flushes it out. I've told probably a hundred homeowners this trick and it makes H01 disappear permanently when there's no actual hardware failure involved. Just make it a habit. Takes a minute, saves you a service call.

What temperature does a Bosch dishwasher need to operate properly?

Bosch recommends 120-140F incoming water. The main wash cycle targets somewhere in that range depending on which cycle you picked. Sanitize cycles on compatible models push up to 155F (68C). If your water heater's set below 120F, the dishwasher's constantly fighting uphill to hit its targets within the timeout window. Most water heaters ship set at 120F but it's worth checking, especially if you moved into an older home.

Can cold weather cause H01?

Yep. Pipes running through exterior walls or unheated crawl spaces get seriously cold in winter. Even with the water heater set right, water cools down on its way to the kitchen. Instead of arriving at 120F it might get there at 85-90F. Now the dishwasher has to heat it an extra 30-40 degrees within the same time limit, and it just can't do it. Insulating those exposed pipes is the real permanent fix. Pre-running the hot tap helps in the meantime.

Why does H01 only appear during winter months?

Cold ambient temps pull heat out of the pipes between cycles. In summer, water sitting in the supply line might be 65-70F. In January, that same water could be 45-55F. That's a 15-25 degree worse starting point, which means the heater has to work way harder to hit the target temp in the same amount of time. If H01 only shows up from November through March, cold supply pipes are basically guaranteed to be the cause. Pre-running hot water helps, but insulating the pipes is the real fix.

How much does the NTC sensor cost to replace on a Bosch dishwasher?

The NTC thermistor runs about $15-35 for the part. Part number 12019697 fits a lot of the 500, 800, and 800 Plus series models. It's honestly one of the easier repairs you can do yourself - you're just pulling a probe out of the sump and swapping a connector. If you're comfortable disconnecting the power and popping off the lower spray arm, you can do this job in under 20 minutes. Labor if you call a tech runs $100-150 on top of the part.

Related Bosch Dishwasher Error Codes

Code: E09Bosch E09: Heating Element Not Working Code: E11Bosch E11 Error: Temperature Sensor (NTC) Fault

Same Fix on Other Brands

Miele dishwasherF52: Miele Dishwasher F52: Heating Timeout

Models Known to Experience H01 Errors

This repair applies to most Bosch dishwashers with this error code. Common model numbers include:

SHPM88Z75N, SHPM88Z55N, SHPK7ZL55N, SHE3AR75UC, SHEM63W55N, SHPM65Z55N, SHE3AR72UC, SHDF78Z55N, SHEM78ZH5N, SHPM98Z75N

Written by

Mike Sullivan

Lead Appliance Repair Technician · 20 years experience

Last verified for technical accuracy on May 1, 2025