Whale Pressure Relief Drain Valve For Gas & Elec Expanse Space Heater - AK1275

Whale Pressure Relief Drain Valve For Gas & Elec Expanse Space Heater - AK1275

The Whale Pressure Relief Drain Valve (AK1275) fits directly onto the Whale Expanse gas & electric space heater and is installed at the water outlet / drain point of the heater’s water circuit.

Its purpose is to:

• Automatically relieve excess pressure

• Drain water from the heater to protect against frost damage

• Act as a safety and frost-protection component

It is an integral safety valve and is mounted inside the vehicle, usually close to the heater body, but positioned so discharged water can drain safely outside.

Applies to:

• Caravans

• Motorhomes

• Campervans

• RVs fitted with Whale Expanse gas & electric space heaters

How is it fitted

Important safety note:
This component forms part of the heater’s water and safety system. Installation should be carried out by a competent installer. Always isolate water and electrical supplies before fitting.

Before you start

• Switch off 12 V and 230 V power to the heater.

• Turn off the water pump and open taps to release pressure.

• Allow the heater to cool completely.

• Tools typically required: adjustable spanner, screwdriver, PTFE tape (if specified), hose clips.

Step-by-step fitting

1. Access the heater

   • Locate the Whale Expanse space heater (commonly under a seat, bed, or cupboard).

   • Remove the service access panel to expose the water connections.

2. Locate the drain/relief port

   • Identify the pressure relief/drain outlet on the heater body.

   • If replacing an existing valve, disconnect and remove the old valve.

3. Fit the pressure relief drain valve

   • Screw or push-fit the AK1275 valve onto the designated heater outlet (depending on heater configuration).

   • Ensure the valve is correctly oriented so it can discharge water downward.

4. Connect the drain hose

   • Attach a drain hose to the valve outlet and route it to the vehicle’s exterior drain point.

   • Secure with a hose clip if required.

   • Ensure the hose runs downhill with no kinks so water can drain freely.

5. Secure and check alignment

   • Confirm the valve is firmly seated and not under stress.

   • Check that surrounding pipework is not twisted or strained.

6. Reassemble and test

   • Refit the heater service cover.

   • Restore water supply and power.

   • Pressurise the system and check for leaks.

   • Test frost-drain operation according to Whale guidance.

Quick fit notes

Product type: Pressure relief & frost drain valve

• Fits: Whale Expanse gas & electric space heaters

• Function: Automatic pressure relief and frost protection

• Location: Heater water outlet / drain point

• Drain routing: Must be connected to an exterior drain hose

• Installation: Competent installer recommended

• Safety role: Protects heater from over-pressure and freezing damage

Pro tip

For reliable frost protection, ensure the drain hose exits below floor level and is not exposed to blockages or ice. Periodically check valve operation as part of routine winterisation.