Vulcan-Hart MHB24E Service Manual page 44

SYMPTOM
Steamer on, boiler will not heat. Reset
switch activated, low water light and high
pressure light not lit, ready light lit.
Pressure relief valve opening or leaking.
Steam output low or slow cooking.
Steamer leaks water.
Boiler water level too high, more than 1"
visible in sight glass.
Boiler does not fill or is slow to fill.
F25154 (February 2004)
VHX SERIES STEAMER - TROUBLESHOOTING
1. Reset switch malfunction.
2. Water Level Control malfunction.
3. Cycling pressure switch out of adjustment or malfunction.
4. High limit pressure switch out of adjustment or malfunction.
5. K3, K4 relays malfunction.
6. Relay board malfunction.
7. Contactor(s) malfunction.
8. Interconnecting wiring malfunction.
1. Pressure relief valve malfunction.
2. Cycling pressure switch out of adjustment or malfunction.
3. High limit pressure switch out of adjustment or malfunction.
1. Cooking Compartments.
A. Blocked steam injector ports. Open door, press door switch
button and verify good steam flow into compartment.
B. Steam solenoid valve clogged or malfunction.
C. Steam intake shut-off valve not adjusted properly.
2. Boiler Base.
A. Cycling pressure switch out of adjustment or malfunction.
B. Steam header line (supply) blockage.
C. Excessive amount of water in condensate tube loop from
boiler to pressure controls.
D. Pressure relief valve leaking.
E. Excessive steam supply line leaks.
1. Water, steam or drain line connections loose (top or base).
2. Heating element gasket not sealing.
3. Heating element mounting plate not sealing.
4. Gauge glass fittings loose.
1. Boiler fill valve malfunction.
2. Water level probes not wired correctly.
3. Lime scale build-up on HL probe.
4. Water level control malfunction.
1. Boiler fill water off or filtering system clogged.
2. Manual blowdown valve on water level probe housing open.
3. Boiler fill valve not receiving power, clogged or malfunction.
4. Boiler blowdown/drain valve clogged and not fully closing.
5. Air equalization tubes clogged.
6. Water level control malfunction.
Page 44 of 48
POSSIBLE CAUSES