First things first: remove the heater

1

This is where the heater was initially fitted. It was vulnerable to water from above and corrosion from below. Also, on a small boat every inch of space is valuable, and its location took up a whole locker. Nothing else could go in there for fear of damaging the heater itself or the wiring and fittings around it.

2

Rather than drill through the bulkheads, the ducting had been looped under and over them. Each bend or twist of the ducting degrades its efficiency in delivering the heat – so, when fitting, runs should be as straight as possible.

3

Previously, a modified stainless steel vent had been used for the single heater outlet rather than a properly-fitted heater vent with a removable access cap for inspection. The build-up of dust and debris can be seen in the old pipe.

4

Of more concern than air ducting was the exhaust pipe from the heater. A single mounting bracket had failed due to corrosion, and the exhaust ran right next to the pipes of the bilge pumps and hung over high-tension cables from the battery.

5

Close-up photographs under flash showed further evidence of corrosion around the exit pipe of the exhaust. This was primarily on the exposed area where the lagging isolating it stopped short.

6

The M6 studs securing the heater unit to the mounting plate were sprayed repeatedly with 3-in-1 penetrating oil and left to soak for as long as possible. The clip retaining the combustion air pipe on the left was also left soaking and the pipe then removed.

7

Here we can see just the superficial effects of what corrosion can do in a moist, salty atmosphere. The exhaust pipe broke away at the joint, and the mounting bolts and clips are seized with rust. Deposits can be seen under the lagging.

8

Once the lagging was stripped away, the air ducting came off reasonably easily. The 60mm ducting was held in place with a 50-70mm Jubilee clip.

9

The angle of the fuel pump is roughly 45°. On the delivery side, 1.5mm white fuel line was connected to the pump by a short piece of 3.5mm fabric fuel pipe. This could now be disconnected, and there was no fuel leakage from the feed side because the pump was not operating.

10

The broken stub of exhaust proved difficult to free up, so in the end I peeled it off like opening a corned beef tin.

11

Like the exhaust pipe, the air ducting also disintegrated and fell in half when I had removed it. Any reservations about tackling the job were now thoroughly dispelled. Clearly, a reinstallation was well overdue.

12

The mounting studs were cleaned and refitted tightly using two nuts, locking one against the other. This is also how the stubborn ones were removed. The stud which sheared off was replaced with a 25mm M6 bolt.