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Recommended Pre-Season Maintenance For HYDRONIC Heaters
Before the cold weather arrives, it is recommended that your HYDRONIC 4 / 5 or 10 heaters receive a preseason check. Please use the recommended tools and follow the procedures as outlined in the heater manual while removing and reinstalling the different heater components. Pre‐season maintenance will make sure that your heater(s) are clean, free running and ready for a trouble free season.
The heaters should be inspected and repaired by an Espar trained mechanic, as follows:
1. Check all electrical connections from the heater to the batteries. Check for wear and abrasion along the length of the harnesses. Repair or replace the harness whenever the harness insulation is broken or damaged. Check the battery connections. Clean any corrosion at the terminals. Replace the battery terminals if the corrosion is severe. Check the fuse for corrosion and the correct rating.
2. Check all clamps and hoses. Replace as required.
3. Check the condition of the exhaust system. Check for holes and breaks in the exhaust piping. Replace the exhaust as necessary.
4. Check the fuel pump filter ‐ clean or replace as necessary. For heaters with external fuel pumps, ensure mounting angle of the fuel pump is in between 15‐35o. An incorrectly mounted fuel pump may lead to excessive carbon issues. Check the fuel lines for possible leaks, loose clamps, etc. Once the entire fuel system has been checked and any issues corrected, it is advisable to do a fuel quantity check.
5. Check and clear clogged weep holes on the side of the heater body. Look for any indication of coolant leakages. If leakage is suspected then remove cover with water pump assembly and inspect and replace “O” rings on water pump housing. Closely inspect the heater waterjacket for leakages and replace “O” ring between waterjacket and heat exchanger. If the waterjacket is cracked, replace it.
6. Remove and replace the glow pin screen. Make sure that the new screen is installed correctly as outlined in the repair manual for the heater.
7. Remove and check the glow pin. If it shows signs of dissimilar color or if the glow pin is in any way distorted, replace it.
8. The coolant pump should be removed and the impeller checked for damage. Any dirt or metal particles on the impeller magnet should be removed and the cavity in the pump should also be cleaned. Please Note: coolant pumps are not covered by warranty if the vehicle’s coolant system is excessively contaminated. Refer to Technical Circular 250.
9. Remove the flame tube and check the condition of the flame tube end. The flame tube should be light brown in color with no excessive carbon on the end of the flame tube. Check for carbon build up on the burner “nose” at the cold end of the flame tube. Any carbon covering the air slots should be removed. Check the inside of the heat exchanger and scrape any loose carbon out from between the fins in the heat exchanger. Re‐install the flame tube replacing all gaskets.
10. Re‐assemble the heater and test operation. The heater should be bench tested for 15‐20 minutes before returning the heater to the vehicle.
11. Regardless of the season, run the heater every month for a minimum period of 15 minutes. This will help the heater to burn away any combustion residue in the burner chamber and prevent corrosion in the waterjacket and decay of “O”rings.
Recommended Pre-Season Maintenance For AIRTRONIC Heaters
It is recommended that the AIRTRONIC heaters receive a pre-season check-up to make sure that the heaters are ready for a trouble-free cold weather season. Always use the recommended tools and follow the procedures as outlined in the manual while removing and reinstalling the heater components.
The heaters should be inspected and repaired by an Espar trained mechanic, as follows:
1. Before initial operation ensure that the heater is not being subjected to external loads by heavy objects being placed over it. This may cause damage to the heater parts and affect its normal operation. Ensure that sufficient clearances, as recommended in the heater manual are being maintained around the heater, even while the vehicle is in operation.
2. Check the return air inlet port and hot air outlet port for any blockages. Inspect the length of ducting for any damage and replace as necessary. Ensure all ducting connections are secure. Discourage heat sensitive materials from being placed too close to the heater, ducting components or hot air outlet ports.
3. Check all electrical connections from the heater to the batteries. Check for wear and abrasion along the length of the harnesses. Repair or replace the harness whenever the harness insulation is broken or damaged. Check the battery connections. Clean any corrosion at the terminals. Replace the battery terminals if the corrosion is severe. Check the fuse for corrosion and the correct rating.
4. Remove the glow pin and if necessary, clean it. If the glow pin shows signs of dissimilar color or distortions, replace it. Inspect the glow pin wires for damage and if necessary, replace it. Remember to clean the glow pin chamber and ensure glow pin ventilation hole is clear of any obstructions, than replace the glow pin.
5. Regardless of its condition, remove and replace the glow pin screen every pre-season. Make sure that the new screen is installed correctly. Install the new screen.
6. Check the condition of the exhaust pipe. Look for any holes or breaks in the exhaust piping. Replace if necessary. Ensure the exhaust pipe is securely located and correctly routed.
7. Check the condition of the combustion air intake tube. Clear any blockages. If damaged, replace it. Ensure that the combustion air intake tube is securely located and correctly routed.
8. Ensure mounting angle of the fuel pump is in between 15-35 degrees. An incorrectly mounted fuel pump may lead to excessive carbon issues. Check the fuel lines for possible leaks, loosened clamps, etc., inspect the filter on the suction side fuel pump filter, clean or replace as necessary. Once the entire fuel system has been checked and any issues corrected, it is advisable to do a fuel quantity check.
9. If the fuel quantity result is above specification, then it will be a cause for excessive carbon issues and the fuel pump should be replaced. If the fuel quantity result is within specifications, but on the higher side, then any possible excessive carbon issues may be corrected by increasing the mounting angel of the fuel pump to the near vertical position. If fuel quantity result is below specification, then it is recommended that the fuel pump may be replaced only if the heater repeatedly flames out during operation.
10. If there are complaints about the heater smoking excessively during operation then remove and check the condition of the burner. The burner should be light brown in color. Clean any carbon build up inside the burner tube. Check the inside of the heat exchanger and scrape out any loose carbon.
11. When reassembling the burner and the heat exchanger use a new thermal insulator. Likewise, when reassembling the blower motor assembly use a new blower gasket.
12. Reassemble the heater and test operation. The heater should be bench tested for 15-20 minutes before returning the heater to the vehicle.
13. Regardless of the season, run the heater every month for a minimum period of 15 minutes. This will help the heater to burn away any combustion residue in the burner chamber. It will ensure that the fuel in the lines to the heater does not gel and solidify and that the heater will start reliably when heating season arrives.
See attached link for details – ESPAR_Technical April20
How To Remove Carbon buildup on Airtronic D2 and D4 Burners
To help identify when a burner has excessive carbon build up, Click here and follow the recommendations.
In the event that the burner / flame tube and combustion chamber of the Airtronic D2 or D4 becomes restricted and the heater fails due to carbon/soot build up it may be possible to clean the burner without disassembling the heater by running the heater in high using Kerosene instead of Diesel.
Since the replacement of a burner with carbon build up is not covered by warranty unless the carbon was caused by a defective heater or component this bulletin will assist in reducing the cost and time of cleaning a burner that has caused the heater to fail due to excessive carbon build up.
The excessive build‐up of carbon in the heater is not a result of normal operation of the heater. The build‐up of excessive carbon or soot in the burner / combustion chamber and flame tube as well as the inside of the heat exchanger is in most a symptom of an underlying problem which is the root cause. Therefore, it is very important to identify and correct the root cause so that the burner does not become restricted again. Please refer to the troubleshooting guide and fault code list to identify the problem. Also refer to the installation instructions to make sure the heater and accessories are installed according to the installation guidelines using the correct parts.
In some cases the carbon build up in the burner may be too severe and the burner would need to be replaced. Unless the root cause of the carbon build up is corrected the replacement or cleaning of the burner will not result in a permanent solution but only a temporary fix.
How To Determine If The Burner Has Excessive Carbon Build up
One way to identify if the burner may have excessive carbon build up is to look into the exhaust outlet of the heater with the flexible exhaust pipe removed. This may be difficult while the heater is installed due to its location but with the assistance of a mirror and a flashlight it can be accomplished.
Another way to find out if the burner has excessive carbon build up is to inspect the glow pin screen chamber and look into the burner as much as possible. If the bottom of the glow pin screen chamber is blocked or partially restricted it may be an indication that the burner could have carbon build up.
In most cases where the heater has failed due to excessive carbon build‐up in the burner the heater may produce a Fault Code 52 which is Safety Time Exceeded. This indicates that the heater was not able to start within its allowed start up time. This may also be accompanied by excessive white smoke.
During the cleaning process of the heater it is likely that hot pieces of carbon will come out of the exhaust pipe of the heater. Make sure that there is nothing on or around the exhaust that could be ignited by these particles. For example, oily rags, fuel spills, the kerosene container or any other flammable material or substance. Do not look into exhaust pipe or expose unprotected part of your body to the exhaust outlet.
It is the responsibility of the technician who is performing this method of carbon removal to ensure all safety regulations for working with fuel, are met during the procedure. Below is a picture of a burner that was cleaned using Kerosene.
Alternate method of cleaning
- Remove the glow pin using the glow pin removal tool, Espar part number 25 2069 01 03 03 and replace the glow pin screen, Espar part number 25 2069 01 03 00. Make sure the ventilation hole on the side of glow pin chamber is completely clear and not restricted or plugged. Clean the glow pin screen chamber with a brush before inserting the new glow pin screen.
- Reassemble the heater back to operating condition.
- Make sure all sources of ignition are kept a safe distance away from the fuel lines and the container of kerosene.
- Remove fuel line from inlet side of fuel pump.
- Replace this fuel line with another section of fuel line which is an appropriate length and secure one end to inlet side of fuel pump and other end into a flammable safe container of Kerosene. Espar plastic fuel tank or another approved container may be used.
- Make sure that the fuel lines and fuel container are not near any sources of heat. Make sure the fuel lines do not touch the exhaust systems of the vehicle, or the Heater.
- Ensure end of fuel line is securely fastened to fuel pump as to not allow any air to enter fuel system during operation.
- Ensure Kerosene container is not placed near the air intake or exhaust of heater; this will prevent any fumes to enter combustion chamber and also prevent any sparks or hot particles from igniting the Kerosene.
- Turn on the heater. This may take several attempts to prime fuel lines.
- Adjust Thermostat or Mini Controller to the highest temperature set point. If necessary, open vehicle doors allowing cool air in. This will ensure that the heater runs in boost.
- Some heaters with excessive carbon build up may not start using kerosene and will give a Fault Code 52: Safety Time Exceeded. These heaters may require that they be disassembled and cleaned manually.
- Allow heater to run in boost for approximately 25‐30 minutes.
- Turn heater off
- After the heater has completed its cool down cycle, the fuel line can be removed from fuel pump and container. Container can be removed from the area and safely stored away.
- Reinstall original fuel line back to inlet side of fuel pump.
- The heater can now be operated as usual.