Baxi Potterton BBU 15 HE manual Pipework, System Controls, Storage Systems

Boiler

Fig. 4

	Copper
Copper	0.5m
0.5m

Flow

Return

Copper

1m

22mm

Open Vent

Air Vent

15mm		Indirect
		Cylinder
Cold
Feed
	Pump

4.0System Details

4.3Pipework

1.The sizes of the flow and return pipes from the boiler should be determined by normal methods according to the requirements of the system.

2.It is recommended that the system is designed for a drop in temperature across the system of between 11&20°C.

3.In systems using non-metallic pipework it is necessary to use copper pipe for the boiler Flow and Return. The copper must extend at least 1 metre from the boiler and include any branches. The copper pipe must not be insulated (Fig. 4).

4.4System Controls

1.	The system in which the appliance is installed should
include a control system.
2.	Such a system would comprise a timer control and a
separate room and/or cylinder thermostat as
appropriate.

	Flow	Radiator
		Circuit
Boiler
	Return

Fully Pumped System

Fig. 5

3. The boiler should be controlled so that it operates
on demand only.
4.5	Fully Pumped Open Vent System (Fig. 5)

1.The sizes of the system pipes should be determined by normal methods.

2.The open vent pipe should be a minimum of 22mm and must rise continuously to a point above the feed and expansion tank.

3.The flow pipe from the boiler form part of the vent pipe. No part of the open vent may contain a valve.

4.Inverted pipe runs must be avoided.

5.On low capacity systems with a maximum available flow rate of less than 8.3l/min (temperature differential ›25°C) an external bypass must be fitted .

6.The bypass must be of the automatic pressure operated type.

4.6Storage Systems

1.For information regarding the use of a Bermuda BBU15 HE boiler with a storage system, contact the appropriate storage system manufacturer.

12© Baxi Heating UK Ltd 2009