The heater portion of a hot water pressure washer requires more maintenance than any other part of the machine. Pressure washer burner maintenance extends past the components that make up your burner assembly. In order for your burner to operate at peak efficiency, your engine, battery, pump, and unloader must be functioning properly.
Keep Your Fuel Clean
A water separating fuel filter should be installed in your burner fuel line. (RACOR or equivalent) The filter should be checked daily and drained, if any water is found in the bowl. The burner fuel tank should be topped off at the end of each work day. (If there is no dead air space in the fuel tank condensation can’t form in the fuel line!) The fuel filter element should be changed every two months regardless of the amount of use or the quality of fuel used. If the fuel becomes contaminated the filter element should be changed prior to using the heater and the fuel should be replaced with fresh clean fuel.
Don’t Waste Fuel
The fuel nozzle should be changed as the seasons change. The burner is set up to raise the temperature of the inlet water to around 110 degrees above the ambient range. In the summer you will need to install a fuel nozzle that has an orifice that is smaller by ¼ of a numbered size. Example: Winter Nozzle Size 2.75 80 degree A. The Summer Nozzle Size should be 2.50 80 degree A. Doing this will assure that your water stays in the same temperature range as the seasons change. Also fuel nozzles wear with use and you will get an uneven fuel pattern which will cause poor ignition and smoking.
Burner electrodes should be changed when you change the fuel nozzles, because they will also wear with use and this wear will create ignition problems. Electrodes must be set properly when they are changed. This setting will vary with the type of heater that you are using. I recommend that you check with a certified repair shop to determine the proper setting for your electrodes.
Burner drive couplings should be replaced yearly because they are made of plastic and will also wear as time passes. Burner tune up kits are offered for different types of burners. These kits contain electrodes and drive couplings as well as other things that you may need. Your vendor of choice should know what you need based on the type of pressure washer that you are using.
Make Sure You Have Enough Power
There are other parts of the Heater that may fail due to use or due to the improper operation of certain other components of your pressure washing system. If the charging system in your engine fails, the battery which provides the electricity for a 12 volt burner will not maintain enough power to operate the burner. Low power to the burner can cause electrical components to fail as a result of this, or they may just cease to operate. For this reason you should test your charging system occasionally. Your engine is designed to charge at a certain rate based on the speed of your engine. If your engine should slow down for any reason this will also cause a loss of charging power thus creating a low voltage issue. If you are using a 120 volt burner system your engine will be driving a belt driven generator which must run at 3600 rpms to maintain the proper voltage output and the proper Hz or voltage frequency. This is set up at the factory by installing the proper drive and driven pulleys and assuring proper belt tension. This speed will be maintained so long as the engine speed remains the same and the belt tension is correct. You must also occasionally check this belt for wear and replace it as needed.
Replace Your Thermostat or High Limit Switch
Pressure washer manufacturers use either an adjustable thermostat or high limit switch to keep the heater from overheating. Either is subject to failure due to excessive pressure spikes in the system, power surges or improper handling of the machine. If either of these units should fail they most commonly fail in the open position which means that your burner won’t work at all. In order to test this condition, you must temporarily bypass the component to verify that it is responsible for causing the problem. If you determine that this is the problem you then must replace it before using the heater. DO NOT OPERATE THE HEATER WITH ANY SAFETY DEVICE BYPASSED!
Replace Your Pressure Switch or Flow Switch
When you release the trigger at the gun, and interrupt the flow of water through the heater, the fire that heats the water must also be stopped. If the burner continues to burn, you will cause a steam explosion. It is for this reason, manufacturers use a pressure switch or high pressure flow switch. Either is subject to failure due to wear, extreme pressure spikes, power surges or abuse. If either of these units should fail they most commonly fail in the open position which means that your burner won’t work at all. In order to test this condition, you must temporarily bypass the component to verify that it is responsible for causing the problem. If you determine that this is the problem you then must replace it before using the heater. DO NOT OPERATE THE HEATER WITH ANY SAFETY DEVICE BYPASSED!
Regular pressure washer burner maintenance will help you avoid costly repairs. If you have any questions about pressure washer burner maintenance, call our experts at 1-800-433-2113. We can help you get the parts you need to keep your machine running at peak efficiency.
This advice is intended for use with oil fired heaters as they pertain to pressure washers only. This is in no way intended for use with any other type of heater.