Mi-T-M pressure washer troubleshooting

Failure of the pressure washer can be caused by a manufacturing defect and improper operation. The table of troubleshooting will help to determine the cause of this breakage and in most cases to repair the devise, if the failure is not related to manufacturing defect.

Mi-T-M WP-SERIES pressure washer troubleshooting

Fault Cause Remedy
Engine will not start – Fuel tank empty Fill fuel tank Clean/replace air filter
– Dirty air filter Drain tank and refil tank with fresh, clean fuel
– Stale fuel
– Water in fuel Connect spark plug wire Replace spark plug
– Spark plug wire disconnected
– Bad spark plug
Unit does not come up to pressure – Pump is sucking air Open water supply and check garden hose
– Strainer is blocked Clean strainer
– Pump not bled to remove air Stop engine, press trigger of gun, start engine and run unit while depressing trigger
– Flow regulation control is set to low pressure Turn control knob to high pressure
– Pump or relief valve defective Have unit repaired by authorized service
Water spray irregular – Nozzle clogged Clean nozzle
– Water supply inadequate Check to see that water supply is on full force or use stationary water source.
– Relief valve incorrectly set Have unit repaired by authorized service
No intake of detergent – Nozzle in improper position Set nozzle to low pressure position
– Detergent metering valve closed Adjust detergent metering valve to desired setting.
– Suction filter clogged Clean filter in suction nozzle Clean nozzle
– Nozzle clogged

Mi-T-M HLP-SERIES pressure washer troubleshooting

SYMPTOM PROBABLE CAUSE REMEDY
Motor will not run. Circuit overload. Motor overload. Determine if voltage is on. If not, check wall breaker or fuse.
Reset thermal overload button on pump motor or thermal overload in electrical box. Contact Customer Service.
No discharge at nozzle when trigger mechanism is squeezed. Water turned off. Check incoming water supply. Increase hose diameter and provide adequate water supply (20 PSI, 6 GPM).
Low or fluctuating pressure. Inadequate water supply. Tighten all water intake connections. Eliminate leaks in intake line.
Pump sucking air. (Prime eliminated.) Close valve or submerge detergent hose into solution. Reprime pump.
High pressure detergent valve is open without the end of the hose inserted into detergent (causes vacuum leak and eliminates prime). Replace kinked high pressure hose. Remove, clean or replace.
Kink in high pressure discharge hose. Remove, clean or replace.
Obstructed or worn spray nozzle. Replace packings.
Damaged or obstructed valve assy, in pump. Repair or replace.
Oil appears milky or foamy. Water in oil. Change pump oil. Fill to proper level.
Oil leaking from pump. Worn seals or o-rings. Contact Customer Service.
Detergent will not siphon. Detergent strainer is not completely submerged in detergent solution. Check, submerge if necessary.
Detergent strainer obstructed. Inspect, clean or replace.
Detergent hose cut, obstructed or kinked.
Detergent adjusting knob turned to “OFF” position. Open adjusting knob.
Water flows back into detergent container. Ball and spring in strainer missing or corroded. Remove, clean or replace.
Water flows from the nozzle when the trigger gun is locked in OFF position. Trigger gun is malfunctioning. Repair or replace.
Before start-up, you smell gas around the machine. Gas is leaking. Go to another location and call your gas supplier for instructions, or if you cannot reach the supplier, call the fire department.
Burner will not ignite. Control switch is not in the “BURNER” position. Check switch position.
Trigger gun is closed. Open trigger gun for pressure.
Defective High Limit Switch Replace switch.
High limit switch override. Unit will automatically reignite when cool.
No fuel. Check gas valve is open.
Check L.P.-Gas tank, refill if empty.
Gas line obstruction. Check gas pressure.
Pilot valve is out. Light Pilot.
Gas valve failure. Replace.
Pilot does not light. Manual pilot valve closed. Open pilot valve.
Gas leak at pilot valve. Call qualified serviceman.
Piezo ignitor.
Pilot ignites but will not stay on when gas cock dial is released. Pilot too far away from thermo- couple.
Thermocouple loose at regulator safety valve.

Mi-T-M HSD-SERIES pressure washer troubleshooting

SYMPTOM PROBABLE CAUSE REMEDY
Burner will not ignite Burner switch is not turned on. Check switch position.
Out of fuel. Refuel.
Trigger gun is closed. Open gun for pressure.
EMF Drive-Belt loose or broken. Adjust or replace as necessary.
Flexible coupler broken. Replace.
Dirty or clogged fuel filter/water separator. Drain or replace as necessary.
Fuel pump sucking air. Tighten all fuel intake connections. Eliminate leaks in intake line.
Fuel pump inoperative. Check pressure, replace if necessary
Fuel pickup screen obstructed. Consult Service Department
Dirty or clogged fuel nozzle. Replace fuel nozzle.
Ignition module. Consult Service Department.
Ignition electrodes damaged or worn. With unit running and trigger gun closed, look through burner sight glass to ensure there is sparking across electrodes.
No voltage. Consult Service Department.
Pressure switch override. Pressure should be over 250 PSI/ 18 Bar to allow burner to come on.
High limit switch override. Allow unit to cool down before reigniting.
Improper burner air adjustment. Adjust
Fuel solenoid valve failure. Replace.
Burner runs erratically. Water in the fuel oil. Drain fuel filter/water separator, drain fuel tank and replace with clean fuel.
Dirty fuel filter/water separator. Replace element.
Dirty fuel nozzle. Replace.
Fuel pickup screen obstructed. Consult Service Department
Improper air adjustment setting. Adjust
Fuel pump malfunctioning. Replace.
Burner runs, but will not heat. Poor or improper fuel supply. Check fuel to ensure it is correct. Drain tank and filter if necessary and refill with proper fuel.
Low fuel pump pressure. Check fuel pump pressure, adjust 01 replace if needed.
Dirty fuel nozzle. Replace.
Fuel pickup screen obstructed. Consult Service Department
Improper air adjustment setting. Adjust
Scale build up in heat exchanger coil. Consult Service Department.
Burner discharges white smoke. Low on fuel. Refuel. If white smoke persists, consult Service Department.
Excessive air supply. Adjust

Mi-T-M HSE-1002-0M10 pressure washer troubleshooting

SYMPTOM PROBABLE CAUSE REMEDY
Pump motor will not run. Circuit overload. Check wall breaker or fuse.
GFCI tripped. Reset.
Motor overload. Reset thermal overload button on pump motor or inside electrical control panel.
Auto Start/Stop Option in use. Point gun in a safe direction an squeeze trigger.
No discharge at nozzle when trigger mechanism is squeezed. Inadequate water supply. Ensure hose is 3/4” diameter and incoming water supply is turned on.
Low or fluctuating pressure. Kink in water inlet hose. Remove kink.
Kink in high pressure discharge hose. Replace kinked high pressure hose.
Water inlet screen obstructed. Remove screen, clean or replace.
Pump sucking air. (Prime eliminated) Tighten all water intake connections Eliminate leaks in intake line.
Adjustable Grip on Dual Lance is not in high pressure mode. Turn grip counterclockwise to move to high pressure.
Obstructed or worn spray nozzle. Remove, clean or replace.
Damaged or obstructed valve assy, on pump.
Pump packings worn. Replace packings.
Unloader/Bypass valve not operating correctly. Repair or replace.
Scale buildup in heat exchanger coil. Descale coil.
Water temperature is too high. Do not allow unit to operate in bypass mode (with the trigger gun closed) for more than three minutes.
Defective valve. Replace.
Oil appears milky or foamy. Water in oil. Change pump oil. Fill to proper level.
Oil leaking from unit. Worn seals or o-rings. Contact Customer Service.
Detergent will not siphon . Detergent strainer is not completely submerged in detergent solution. Check, submerge if necessary.
Detergent strainer obstructed. Inspect, clean or replace.
Detergent hose cut, obstructed or kinkea. Inspect, clean or replace.
Detergent adjusting knob turned to closed position. Open adjusting knob.
Detergent will not siphon into the Low Pressure Mode. Adjustable grip on dual lance is not in low pressure mode. Turn grip clockwise to move to low pressure.
Too many high pressure hose extensions attached to the water outlet. Use one extension maximum.
Nozzle assembly is plugged. Clean or replace.
Ball & Spring in Venturi stuck. Remove, clean or replace.
Water flows back into detergent container. Check valve missing or corroded. Remove, clean or replace.
Water flows from the nozzle when the trigger gun is locked in the “OFF” position. Trigger gun is malfunctioning. Repair or replace.
Water is leaking under heat exchanger coil. Coil drain plug is not installed. Install.
Safety Relief device is relieving caused by an unloader or pressure switch malfunction. 1. Detect and correct unloader or pressure switch problem.
2. Replace safety relief device. NEVER run unit without safety relief device. Doing so can cause an explosion!
Burner will not ignite Switch is not in “Burner” position. Check switch position.
No voltage. Contact Customer Service.
Out of fuel. Refuel. (Reset burner primary control on cad cell options.)
Fuel tank inlet tube screen obstructed. Remove, clean or replace tube.
Trigger gun is closed. Open trigger gun for pressure.
Pressure switch override. Pressure should be over 250 PSI to allow burner to come on.
High limit switch override. Unit will automatically reignite when cool.
Flexible coupler broken. Replace.
Dirty or clogged fuel filter/water sep. Drain or replace as necessary.
Fuel pump sucking air. Tighten all fuel intake connections. Eliminate leaks in intake line.
Fuel pump inoperative. Check pressure, replace if needed.
Dirty or clogged fuel nozzle. Replace.
Improper burner air adjustment. Adjust
Ignition transformer failure. Replace.

Mi-T-M pressure washer troubleshooting

TROUBLE POSSIBLE CAUSE REMEDY
Low Pressure Loose belt on pump Tighten pump
Leaks in water system Tighten all fittings
Insufficient water supply Fill tank or increase line size to machine
Outlet orifice worn or wrong size Replace with correct orifice.
CAUTION: Do not use smaller than recommended. Excessive pressure will damage pump.
Gun control unloader valve bypass leak Repair or replace unloader valve
Dirty or worn check valves in pump Replace or clean. Refer to high pressure pump manual.
Cylinder cups leaking and/or worn cylinder sleeves Replace. Refer to high pressure pump manual.
Excessive Pressure Outlet orifice restricted Remove orifice at tip of gun and clean. Flush coil with water before replacing.
Scale or dirt in coils Descale coils
Pump speed too high Check water output GPM
Relief Valve Operates Relief valve set at low pressure Re-adjust relief valve Replace valve
Relief valve dripping after adjustment
Unloader valve stuck Repair unloader valve
Weak or no chemical at nozzle Clogged soap screens Air leak around soap siphon Clean or replace
Tighten all fittings and tubings check valve and/or metering valve leaking
Pump motor heating or overloading Motor wet Allow to dry. Have motor checked by qualified repair station.
Pump motor heating and clean. Outlet orifice restricted Undersize outlet orifice Remove orifice at tip of gun or overloading Replace with correct size
Coil scaling up Descale coil
Water pump out of oil Fill to correct level. Check for leaks
Overload switch operated Allow motor to cool CAUTION: Switch may automatically reset.
Faulty motor Repair or replace
Water temperature too low Thermostat adjustment Coils liming up Adjust the thermostat to desired temperature