Installation manual

TWIN FLOW CONDENSATE DISPOSAL

The boiler condensate drain combines the pressure relief and condensate drain

together. The condensate side has an internal trap to prevent by-products of

combustion entering the room.

Condensate and Pressure Relief Discharge Disposal.

Disposal of the condensate/pressure relief water must be done in accordance with

BS 6798:2000, the Building Regulations Part H, Building Regulation G3, and any

local building controls.

These rules should be followed when piping the discharge.

1. A minimum distance of 300mm must be between the bottom of the

tundish and the first bend.

2. Do not reduce the size of the drain pipework

3. The pipe work must have an air gap

4. Maximum run is 3m between boiler and air gap

5. Air gap must be within the thermal envelope.

6. Any bends should be close to the boiler

7. The pipe may not rise above the boiler connection point

8. The pipe may not have any low spots that will collect water. The

pipe work must drain dry.

8. The discharge must flow to a safe place for disposal away from the

boiler that is visible

9. The discharge must not create a hazard to the building, contents, or

inhabitants. Scalding injury or water damage can occur if the

drainage pipe work is incorrect.

The condensate can be drained externally into a gully or a soak away. The

condensate can also be drained inside the building into an internal stack, or

combined with the drain from an internal fixture. The various methods are shown in

the diagrams on the following page. If a stack is used for discharge then a trap must

be placed in between the tundish and the stack to prevent smells from entering the

room.

Pipework must be at least 22mm, consider using larger pipe work if there is a risk of

freezing. External pipe work should be as short as possible, and must be less than

3m. All external condensate pipe work must be at least 32mm and insulated to

protect from freezing, especially the trap. If the pipework is exposed the insulation

must be waterproof.

All condensate pipework must fall with at least a 2.5

angle from the horizontal (this

is 50mm drop per horizontal metre. The pipe work must be drain material such as

PVC, uPVC, ABS, or PP. Copper cannot be used. The pipework should be

bracketed to prevent sagging.

The condensate pipe work shall not have any tap, valve, or restriction in the line.