Aquahot: Replacement Procedure

by Bob & Faith Rozek 1997 U320 40′

About two months ago I began searching for the reason why the coolant level in the expansion tank kept dropping. I discovered where it was going when the unit was operating on diesel. What I thought was smoke coming out of the exhaust pipe turned out to be a coolant leak in the combustion chamber. I purchased the replacement through Roger Berke and was very pleased with his service. I completed the installation today and I’m happy to have it behind me!! The removal and installation are labor-intensive but it can be done if you are physically capable of bending your body into a pretzel!! If anyone has questions, I would be happy to share what I’ve learned through my process.

Aqua-Hot rebuilds the returned units when an order comes in. All parts must be returned to receive the $1000 core refund. If any parts are missing they start reducing that amount.

AquaHot will not sell a “boiler” separately. I even looked at other options besides AquaHot, but it was the only logical way to go.

Materials cost: In the 7K range, with $1000 core refund from Aqua-Hot

Procedure:

1. Secure all power (12V & 110V) to the unit.

2. Disconnect all wiring. Carefully mark all 12V wires. These wires will probably get wet at some point so make sure your labels/ink is waterproof.

3. Secure/cut potable water source. PVC cutter works well for all of the tubing’s/hoses.

4. Drain heater coolant/water mixture.

5. Remove hold-down bolts. There are bolts on the back side that will require the use of a mirror, flashlight and long extension to remove. 

6. Mark all zone hoses/tubing and cut loose from the unit. I bought rubber plugs to seal off hoses/tubing to reduce fluid loss and air in the system.

7. Mark/cut engine preheat hoses. Seal hoses with plugs.

8. Mark/cut diesel fuel lines. I coupled the two together as I had a spare 1/4″ barbed connector.

9. Cut off exhaust pipe at first elbow.

10. Block up AH high enough access exhaust pipe. It has to be cut off flush with the unit.

11. Remove unit from the compartment.

12. Reverse procedure for installation.