Whale Pressure Relief Drain Valve For 8/13 Ltr Gas and Elec Water Heater - AK1205

Whale Pressure Relief Drain Valve For 8/13 Ltr Gas and Elec Water Heater - AK1205

The Whale Pressure Relief Drain Valve (AK1205) fits directly onto Whale 8-litre and 13-litre gas & electric water heaters.
It installs on the heater’s cold-water outlet / drain connection and forms part of the safety and frost-protection system.

Its job is to:

• Relieve excess pressure in the water heater

• Automatically drain water to protect the heater from frost damage

• Safely discharge water via a drain hose routed outside the vehicle

This valve is installed inside the vehicle, close to the heater body, with a hose leading through the floor or wall to the exterior.

Typical applications: caravans, motorhomes, campervans and RVs fitted with Whale 8 L or 13 L gas & electric water heaters.

How is it fitted

⚠️ Safety notice:
This valve is part of the heater’s water safety system. Installation should be carried out by a competent installer. Always isolate water and power supplies before fitting.

Before you start

• Switch OFF the water pump and open a tap to release pressure.

• Isolate 12 V and 230 V supplies to the heater.

• Allow the heater to cool fully.

• Tools typically required: adjustable spanner, screwdriver, hose clip(s), PTFE tape (if specified by the heater).

Step-by-step fitting

1. Access the water heater

   • Locate the Whale water heater (often under a seat, bed, or cupboard).

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

2. Identify the drain/relief connection

   • Find the heater’s pressure relief / drain outlet on the cold-water side.

   • If replacing a valve, disconnect and remove the existing unit.

3. Install the pressure relief drain valve

   • Fit the AK1205 valve onto the heater outlet (threaded or push-fit depending on model).

   • Ensure it is fully seated and oriented so the outlet points downward.

4. Attach the drain hose

   • Connect a suitable drain hose to the valve outlet.

   • Route the hose to an exterior drain point (through the floor or side wall).

   • Secure with a hose clip and ensure the hose runs downhill with no kinks.

5. Check alignment and security

   • Make sure the valve and hose are not under strain.

   • Confirm there is clear space for the valve to operate freely.

6. Reassemble and test

   • Refit the service panel.

   • Restore water supply and power.

   • Pressurise the system and check for leaks.

   • Verify the valve drains correctly during winterisation/frost conditions.

Quick fit notes

• Product type: Pressure relief & frost-protection drain valve

• Fits: Whale 8 L and 13 L gas & electric water heaters

• Location: Heater cold-water outlet / drain point

• Drain routing: Hose must exit outside the vehicle

• Function: Protects heater from over-pressure and freezing

• Installation: Competent installer recommended

Pro tip

For reliable frost protection, keep the drain hose short, straight and unobstructed, and check valve operation as part of your winterisation routine

This valve is compatible with various models in the Whale Rapid Heat water heater range, including:

• WH0802 (B/BR)
• WH0822 (B/BR)
• WH1302 (B/BR)
• WH1312B
• WI0802 (B/BR)
• WL0802R