A two-outlet install: heat to the salon, and to the aft cabin where clothes hang. The V-berth stays unheated. It runs at the dock and at anchor from the 660 Ah lithium house bank.
Schematic, not to scale. The exhaust outlet sits lower than the heater so condensate drains out through the fitting. The day tank sits in its tray at least 30 cm from the heater body and the exhaust. Its vent hose climbs in a loop before it leaves the hull, so a heel or a full tank cannot push diesel out of it.
Petrichor's main tank sits to port between the galley and the salon, a long way from the heater. The dosing pump wants to sit near its tank and pushes better than it pulls, so a small day tank beside the heater suits this boat. The main tank stays as it is. Never tee into the engine supply: the heater pump pulls air into the engine line.
Diesel needs heating past about 52 °C before it gives off enough vapour to light, so a sealed day tank is a spill and smell risk more than a fire risk. Three things keep it that way: the tray catches a leak, the straps stop the tank moving, and the 30 cm gap keeps it away from the hot parts.
A standpipe through the fuel-level sender plate, drilled at the bench, keeps chips out of the tank. It means a fuel line from the port side, past the engine, to the locker. The day tank installation stays useful for a move like this: only the tank end of the line changes.
Tell the insurer before cutting holes: some ask for an ABYC A-7 install or a surveyor's look. Order the marine parts the kit lacks (list below) so the job runs end to end.
Bond a plywood or G10 base to the locker, high enough to stay dry with water in the bilge. Bolt the heater through it with the kit's gasket. Keep it in the attitude the manual allows, away from sails, lines and anything that burns.
Fit the intake silencer on a short pipe, open end pointing down, inside the locker, well away from the exhaust. The locker must breathe: if it seals tight, add a vent to outside.
Bond the drip tray to the locker floor and strap the tank into it. Fit the vent fitting outside and run the vent hose up in a loop to it. Keep the tank at least 30 cm from the heater body and the exhaust.
Duct the heater's inlet to a grille in the aft cabin, so it warms cabin air rather than locker air. Fit a mesh filter behind the grille. With six aboard, open a dorade or crack a hatch at night: the heater does not ventilate the boat.
| Part | Why | Replaces |
|---|---|---|
| Double-wall stainless exhaust skin fitting, 24 mm | Keeps transom heat down, seals the hull | Kit's car-style exhaust end |
| Stainless exhaust hose, 24 mm, and lagging | Kit flex pipe corrodes and leaks fumes in salt air | Kit exhaust pipe |
| Day tank, 10 to 20 L, diesel-rated, with outlet fitting and sealed cap | Heater fuel beside the heater; main tank untouched | Kit's plastic tank, if supplied |
| Drip tray and two ratchet straps or stainless bands | Catches a leak, holds the tank in a seaway | |
| Vent hose and a small vent fitting | Keeps diesel smell out of the locker | |
| Closable outlet, fixed outlet, Y-splitter | Two-zone heat, sized to the heater's duct | Kit's single outlet |
| Insulated duct, 3 to 6 m | Heat arrives where it is wanted | Kit duct, if short |
| Return-air grille with mesh filter | Draws cabin air, keeps lint out of the fan | |
| Plywood or G10 base, stainless fasteners | Dry, solid mount off the hull | |
| 10 AWG tinned wire, fuse holder at the bus | Clean start current without voltage sag | Kit battery leads |
| Marine CO alarms, three | V-berth, salon, aft cabin |
Fit a marine-rated CO alarm in each sleeping space before the first night aboard with the heater on. Six people asleep in a closed boat is the case the install has to survive.
At anchor the boat lies bow to the wind and the stern exhaust blows clear. At the Shilshole slip, wind from astern can push it into the cockpit and the companionway. Check the cockpit with a CO alarm on a breezy day.
Keep the exhaust and the heater body clear of fuel hose, wiring, sails and lines, and at least 30 cm from the day tank. Keep the exhaust outlet well away from the fuel fill and both tank vents.