What You Need

Hole Positions

Decide first if you want to install the coil on the left or right side of your kettle. You should minimize the distance from the coil fittings to your MLT. If the MLT is to the right of the HLT, install the coil on the right side. If your MLT is to the left of your HLT, install the coil on the left side. 

The coil passes through two holes in the kettle sidewall. The position of these holes is critical — too high and the coil will not be fully submerged at low wort levels; too low and it will collide with your heating element. Use the dimension drawings below for your kettle size which ensure approximately 1cm clearance from the heating elements to the coil. Measurements are from the bottom of the kettle to the center of each hole.

Kettle	Lower hole — centre from bottom	Upper hole — centre from bottom
40L	132 mm	272 mm
60L	153 mm	293 mm
85L	209 mm	309 mm

Mark both hole positions clearly on the outside of the kettle sidewall with a marker before drilling. Double-check both positions against the drawing before picking up the drill.

 

Drilling the Pilot Hole

The hole punch requires a pilot hole through which its bolt passes. The punch does all the work of cutting the final hole to size.

1. Mark the hole position on the kettle sidewall using the dimension drawing for your kettle size. 
2. Place the kettle on a stable surface. Apply a small amount of cutting oil to the drill bit and the marked position. Drill slowly through the kettle sidewall with a 10 mm drill bit. Keep steady pressure and do not allow the bit to drift off centre. 
3. Repeat for the second hole position.

Using the Hole Punch

The Q-Max hole punch threads its bolt through the 10 mm pilot hole and draws a hardened cutting die through the stainless wall, producing a clean round hole sized precisely for the coil fitting.

1. Place the kettle on the ground on a folded towel to protect the exterior finish. 
2. Thread the punch bolt through the pilot hole from the outside of the kettle. Place the cutting die on the inside and thread it onto the bolt by hand. Tighten with a spanner — the die will draw through the wall and cut a clean hole. Apply steady, even torque; do not rush.
3. The inside of the hole will be fairly clean. The outside edge will be rough and must be deburred — see the next section. Repeat for the second hole.

Deburring the Holes

The inner edge of each punched hole will have a slight burr from the cutting action. This must be removed before installing the coil. The coil fitting uses O-rings that seat directly against the hole edge — any burr or sharp edge will damage the O-ring and cause a leak.

1. Use a metal file or sandpaper to smooth the edge of each hole. Work around the full circumference — the goal is a smooth, chamfered edge with no sharp points or rough patches.
2. Run a finger carefully around the inside edge of each hole. It should feel smooth with no snagging points.
3. Wash the kettle thoroughly to remove all swarf, metal dust, and oil before proceeding.

Installing the Coil

The coil comes with a locknut and O-rings for each port. The locknut has a groove on each face that captures one O-ring — one O-ring seats against the inside of the kettle wall, one against the outside, creating a watertight seal on both sides of the stainless.

1. Place one O-ring in the inner groove of the locknut. 
2. Pass the coil fitting through the hole from inside the kettle. 
3. Place the second O-ring on the outside of the fitting against the kettle wall. Thread the locknut onto the fitting from the outside and tighten firmly by hand, then snug with a spanner. Do not overtighten — the O-rings seal at moderate torque. Check that both O-rings are seated evenly and have not been displaced.
4. Repeat for the second coil port.
5. Thread the Tri-Clamp adapter onto each fitting. The adapter includes a flat gasket — no PTFE tape is required. Hand-tighten the adapter until the gasket seats, then snug with a spanner.

   Standard coil (½" BSP thread): ½" BSP IG → Tri-Clamp adapter

   High-flow coil (1" BSP thread): 1" BSP IG → Tri-Clamp adapter

Testing and First Use

Leak Test

Before connecting the coil to your recirculation pump or using it in a brew session, perform a cold leak test:

• Fill the HLT kettle with clean cold water to a level above both coil ports
• Connect hoses to both Tri-Clamp adapters and run your pump at low flow for several minutes
• Inspect all four sealing points — both inner O-rings and both Tri-Clamp adapter joints — for any weeping or dripping
• If a joint weeps, stop the pump, dry the area, and check that the O-ring is properly seated and the adapter is fully tightened

Cleaning Before First Brew

Run a full cleaning cycle through the coil before using it with wort for the first time. Circulate a food-safe brewery cleaner such as PBW or Chemipro Oxi through the coil at the recommended concentration and temperature for at least 20 minutes, then rinse thoroughly with clean water. This removes any manufacturing residue from the coil interior.