Hobart lx30H Fuse f1 3.2amp 250vac blown, f1 feeds relay board. No booster temp, pump and sump heater active (OK). Can problem be from other devices that are driven from the low power relays on this board or are we looking at a board failure as the only answer. No skinny on door panel, Can't get access to OEM repair manuals anywhere on line Thanks

If your Hobart AM15 dishwasher is displaying an AH error code on start up, it usually indicates that there is an issue with the booster heater. AH stands for "Booster Heater Circuit".
Here are some troubleshooting steps you can follow to resolve the issue:

1. Check the booster heater temperature sensor. It may be dirty or faulty, preventing the booster heater from functioning properly. Clean or replace the temperature sensor if necessary.
2. Check the booster heater element for continuity. If the element is broken, it will need to be replaced.
3. Inspect the wiring and connections between the booster heater and the control board. Loose or damaged connections can prevent the booster heater from functioning properly.
4. Check the booster heater relay on the control board. If the relay is faulty, it will need to be replaced.

If none of these steps resolve the issue, you may need to contact a professional technician to diagnose and repair the problem.

The fill solenoid is behind the lower panel, attached to the left side of the booster tank. There is a screen in the end of the fill hose that may be clogged. You require 20 psi flow rate to run the machine properly.
Pull the top tray out, place a magnet on the door switch, with the door closed and monitor the 3 led lights on the control board while its filling. All 3 should light up. Use caution around the high voltages present on the relay board and the booster contactor.
The probes in the right rear corner of the tank send the water level signals to the control board. The tips must be clean of scale or debris that may signal that water is present, when it is not.

I have to asume the wiring connections had not changed since it last worked.
There are three versions. LX18, LX18C and LX18H.
Inspect the relay board for damage. The connections can come loose and melt relays.
It could also be the wash sump tank heater or the booster heater if it's an H. The other two only have a sump heater. If you power it on, and have no water in it's tanks, the elements can glow red hot till they trip the high limits.

Check the heat circuit of your dishwasher. This will include your control, heat element, thermostat/thermal fuse, & sometimes your door switch. Check your thermostat/thermal fuse and heat element for continuity first. If all test good, go to your control and possibly your door switch. Check for voltage from your control and continuity of your door switch.Use the VOM. God bless you

What type of detergent is not necessarily important - anything intented for use in commercial dishwashers should be sufficient. A restaurant supply store should have something suitable for you.
Also, in case you don't already know, the LX30C is the non-booster-heater version of the LX30 (LX30H has a booster heater). Without a booster heater, you'll need to use chemical sanitizer. The LX30C should, hopefully, have a sanitizer pump installed to inject chemical sanitizer into the rinsewater stream. Most of these dishwashers also have a detergent pump to inject detergent into the wash tank and rinse aid pump for chemical rinse aid.
If present, these pumps are located in the bottom of the machine. Remove the lower front panel (2 screws) and look for the small, black plastic assemblies with 2 hoses connected to each.

The main cause is the "anti flood" device at the bottom of the washer that detects a water leak "hose leak" etc. This device made up of a polystireen float and micro switch is a safety device and when activated puts the washer in pump out mode only. You need to look at the base of the washer and see if water leak has caused this. Rectify the cause "normaly hose or clamp" and this should clear the

the supply to the d/w should be at least 120degrees.the p2 error is a bad booster probe. always use hot water feed

This is a bad sump temperature probe. The unit will function, but will not heat nor display the wash water temperature.

This is a very easy fix. Order Hobart part number 328994 from your nearest Hobart parts dept.

Turn off and drain the unit. Kill the power to the unit at the circuit breaker. Remove the lower front cover. Locate the screw-in temperature probe at the front of the sump. Unplug the sensor from the wiring harness, remove with a 7/16" open end wrench. Screw in the new probe, using teflon tape of the threads, snuggly. It does not need to be super tight. Plug it into the harness, reinstall the front cover, turn the breaker back on, and start up the unit.

TURN THE BREAKER OFF AS EVEN WITH THE UNIT "OFF" THERE WILL BE 120 VOLTS PRESENT AT THE SUMP HEATER (yellow wires) DUE TO ONLY ONE LEG OF POWER BEING SWITCHED OFF!

The booster heat control circuit is controlled by the relay board. Visually check for loose or burnt relay contacts...
You will see the booster LED light when it calls for heat. Some newer machines have a second high limit on the right hand side of the booster tank.
It may be your control board is configured for low temp with no booster. When you power up, the display should say LX30H. If not
Pull open the upper drawer, place a magnet over the door interlock switch.

CAUTION, 220 volt power is present. be carefull what you touch.

on control board, short J5-1 and J5-2, then power up. You are in factory setup. press select on the control board to see each option on the front panel., press up arrow on control board to step up through options for each step. when done, press the off button on front panel. remove short and start up normally. With the magnet in place, AND THE DOOR CLOSED, run the machine and observe the relay board status lights.
If you want to adjust the temp set points, with the machine off, press and hold the hidden key behind the front panel logo, and press select on the control board.. Or on power up, hold the wask key..Same to adjust options as above. Press off to exit.

Hopefully you took the suggestion to run the correct 50 amp 208-240 service to the unit.

Converting the unit to an LX30C has a couple of pitfalls. The LX30C is connected directly to the incoming water supply, which should run 120-140 degrees. By reprogramming the unit as an LX30C, the booster would be disabled, which would mean the incoming water would flow through the de-energized booster and be cooling off while it sits in there between cycles and when the unit is shut down.

The incoming fill plumbing (5/8" heater hose) would have to reconnected from the fill solenoid valve directly to the vacuum breaker on the rear of the unit to bypass the booster heater.

On the 208-240 volt LX18/30/40's, the pump motor, booster heater, and sump heater run on 208-240. To convert it to 120 volts you would have to replace the sump heater and reconfigure the motor wiring in the motor junction box.

By the time this is all done, you've downgraded a great machine, confused the next service guy, and have to deal with nasty chlorine and all of it's headaches.

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