Baxi 47 075 35 Installation & Servicing Instructions Manual page 20

1. If the boiler is fitted in a room containing a bath or shower and NOT FITTED with any optional integral timer or thermostat, it can be
fitted in zone 2, (Figs. A & B shows zone dimensions for a bathtub. For other examples refer to the Current I.E.E. Wiring
Regulations) reference must be made to the relevant requirements.
In GB this is the current I.E.E. Wiring Regulations and Building Regulations.
In IE reference should be made to the current edition of I.S. 813 "Domestic Gas Installations" and the current ETCI rules.
Fig. B
page 16
7.7 Condensate Drain
FAILURE TO INSTALL THE CONDENSATE DISCHARGE PIPEWORK CORRECTLY
WILL AFFECT THE RELIABLE OPERATION OF THE BOILER.
CAREFUL CONSIDERATION MUST BE GIVEN TO THE POSSIBILITY OF THE
PIPEWORK BEING SUBJECT TO FREEZING CONDITIONS AND APPROPRIATE
MEASURES TAKEN TO PREVENT BLOCKAGE. CORRECT INSTALLATION IN
ACCORDANCE WITH THIS SECTION WILL CONSIDERABLY MINIMISE THE
LIKELIHOOD OF BLOCKAGE AND SUBSEQUENT BOILER LOCK­OUT.
A CONDENSATE DISCHARGE PUMP AND PIPE 'TRACE HEATING' ARE
AVAILABLE AS ACCESSORIES ­ see paragraphs 7.7.12 to 7.715 for further details.
The condensate discharge pipe MUST NOT RISE at any point along its length.
There MUST be a fall of AT LEAST 2.5° (50mm per metre) along the entire run EXCEPT
when employing a suitable condensate pump in basement and cellar or similar applications.
The boiler condensate trap incorporates a seal of 75mm, therefore it is unnecessary to
install an air break and trap in the discharge pipework.
1. The condensate outlet will accept 21.5mm (3/4in) plastic overflow pipe. It is strongly recommended that this discharges
internally into the household drainage system. Where this is not possible, discharge into an outside drain is permissible
providing every possible precaution is taken to prevent freezing.
2. Ensure the discharge of condensate complies with any national or local regulations in force. BS 6798 & Part H1 of the Building
Regulations give further detailed guidance.
3. The discharge pipe should be run in a proprietary drain pipe material e.g. PVC, PVC­U, ABS, PVC­C or PP.
4. Metal pipework is NOT suitable for use in condensate discharge systems.
5. The pipe should be a minimum of 21.5mm diameter and must be supported using suitably spaced clips of the correct design to
prevent sagging.
6. It is advisable that the full length of condensate pipe is run internally and preferably be less than 3 metres.
7. Internal runs greater than 3 metres or runs in cold areas should use 32mm waste pipe.
8. External runs MUST be a MINIMUM of 32mm and fully insulated with material suitable for external use.
9. If the boiler is fitted in an unheated location the entire condensate discharge pipe should be treated as an external run and sized and
insulated accordingly.
10. In all cases discharge pipe must be installed to aid disposal of the condensate. To reduce the risk of condensate being trapped, as
few bends and fittings as possible should be used and any burrs on cut pipe removed.
Examples are shown of the following methods of termination:­
i) to an internal soil & vent pipe
ii) via an internal discharge branch (e.g. sink waste) downstream of the trap
iii) to a drain or gully
iv) to a purpose made soakaway