Top Technical Questions Answered

System specification, legislation, problem solving and product innovation – the heating sector is an ever-changing environment, and installers are on the front line.

Thank goodness then for the manufacturer’s technical support teams, ready and waiting to share their expertise, whatever the issue. Here, Damian Delaney, training manager at Baxi Potterton Myson, makes life even easier by sharing the answers to his top five most asked questions.

Always under pressure to get the job done quickly, and sometimes out on the road alone, even experienced installers often find themselves in need of a helping hand from a like-minded technician. As a result, the technical support offered by manufacturers is a vital resource, as they can offer both general and product-specific advice, normally instantly. We are asked all kinds of questions – from which Baxi boiler we would most recommend, to resistance readings on key components. But here we have focused on the top five most asked questions. We hope you find them useful!

Question 1: How do I reset the service due (SD) message on the Baxi GA range of boilers?

To reset SD you would carry out the following:

Step 1: Press IIII• – and IIII• + for 6 seconds. Using IIII• + scroll through until ‘22’ is displayed. Press ‘i P’.

Step 2: Press IIII• + to scroll to ‘15’. Confirm with ‘i P’ then press R to return the display to normal.

The process is also printed in the installation guide for the boiler.

Question 2: How do I connect the air pressure switch on a standard efficiency Baxi Combi 80e?

The air pressure switch will have three contacts: 1: common (c)

2: normally closed (n/c),and

3: normally open (n/o

Firstly you will need to check to see if the boiler has two wires – brown and blue – or three wires – black, brown and blue – connected to the air pressure switch (APS). If the APS is a two-wire type you connect the brown to 1 common (c) and blue to 3 normally open (n/o). When the boiler is off and no fan is running, 1 brown and 3 blue will have no continuity. Then on demand the fan will run, making the APS create a circuit between 1 common (c) and 3 normally open (n/o). This is a simple two-wired switch.

For the three-wire APS, you would connect black to 1 common (c), brown to 2 normally closed (n/c) and blue to 3 normally open (n/o). When at rest with no fan running, the switch will have continuity between 1 common (c) and 2 normally closed (n/c). Then on demand, the fan will run, moving the APS to 3 normally open (n/o) position, creating a circuit between 1 common (c) and 3 normally open (n/o).

The positive and negative sensing tubes will always connect P1 + positive and P2 – negative.

Question 3: How do I access service function (SF) on a Baxi Duo Tec HEA?

Make sure there is a call for central heating and turn the two dials on the front of the boiler fully anticlockwise. Then quickly turn the right hand dial a quarter turn clockwise then back to zero – do this twice. The display should then show ‘SF’ and the two lights either side of the display will flash green.

Turning the left hand dial will alternate the boiler between minimum and maximum; ‘00’ indicates maximum, a ‘0’ indicates minimum. After carrying out the FGA and checking that the levels are within tolerance, to exit ‘SF’ simply turn the right hand dial.

Question 4: What are the minimum clearances for flue terminations?

Flue clearances are manufacturerspecific, and are listed in the installation instructions supplied with the boiler. If the clearance you require is not listed in the manual you will need to refer to I.S. 813 for guidance.

Question 5: Which boiler replaces the current model?

The answer depends on what type of boiler your current model is – heat only, system or combination. The Baxi Potterton Myson website provides guidance on replacement boilers and also has a “find a boiler” feature, which will recommend a boiler based on the size of property

Visit www.baxipottertonmyson.ie for more information.