Mill Hill Cottage Plumbing & Heating Ltd

(Previously Heating Innovations)

Heat pump only mode

On the H7 control box the automatic boiler boost switch is moved to the central off position and heat pump switched on allowing the ground or air source heat pump to operate independently (this mode might be useful in events such as the automatic boiler requiring maintenance.)

When fitted, heat leak radiator has circuit at all times

Function 1.

Hot water mode on and cylinder thermostat is calling,

Heating mode off, or room thermostat is satisfied

Heat pump is running, charging the hot water cylinder.

Status.

	Motorized Valve no 8 - Naturally Open to the heat pump. (closed to the automatic boiler)
	Motorized Valve no 10/17 - Naturally Open to the hot water cylinder. (closed to the radiators)
	Motorized Valve no 22 - Naturally Open to common return (closed to the heat pump).

Red = Flow. Blue = Return. Orange = Preheated Return. White = Not flowing.

Function 2.

Hot water mode on and cylinder thermostat is calling,

Heating mode on and room thermostat is calling

As above in function 1, Heat pump is running, but in hot water and heating mode motorized Valve no 10/17 is motored to mid position and the heat is diverted to both the hot water cylinder and the radiator/U.F.H. system.

Status.

	Motorized Valve no 8 - Naturally Open to the heat pump. (closed to the automatic boiler)
	Motorized Valve no 10/17 Motored to mid position. open to the hot water cylinder & radiators/U.F.H.
	Motorized Valve no 22 - Naturally Open to common return (closed to the heat pump).

Red = Flow. Blue = Return. Orange = Preheated Return. White = Not flowing.

Function 3.

Hot water mode on and cylinder thermostat is satisfied

Heating mode on and room thermostat is calling

When the hot water cylinder reaches optimum temperature (detected by the cylinder thermostat), motorized Valve no 10/17 is motored open to the radiators/U.F.H. and closed to the hot water cylinder.

Status.

	Motorized Valve no 8 - Naturally Open to the heat pump. (closed to the automatic boiler)
	Motorized Valve no 10/17 Motored open to the radiators/U.F.H. & closed to the hot water cylinder
	Motorized Valve no 22 - Naturally Open to common return (closed to the heat pump).

Red = Flow. Blue = Return. Orange = Preheated Return. White = Not flowing.

Contact Mill Cottage Plumbing & Heating Ltd

Technical Support and Sales

Telephone 01354 653854