Most problems shown on this page are indicated by the boilers red led flashing. This light simply indicates that the boiler has identified a fault and gone into 'lockout' mode. Unfortunately their is no 'fault code' available to indicate what the underlying problem may be.

The fixes shown on this page are not guaranteed to resolve any problem currently being experienced with your Suprima boiler but do appear to be the most common causes of problems. The authors of this site will not be held responsible for any costs or damages incurred by following these instructions, they appear here for information only and represent the experiences of the authors and contributors.

Always isolate (switch off) the electrical supply before removing any covers on your boiler.

PCB

There have been numerous reports that the soldered joints on the main circuit board (PCB) develop hairline cracks and need resoldering. Additionally, several people have reported that some of the board's components themselves have failed.

The most common sympton of PCB problems is the boiler going into 'lockout' mode after having been running for a while.

If you do have a problem with your PCB, fitting a new one is relatively easy, the only tool you will need is a philips (cross-head) screwdriver. The main decision is whether to go for a new board or a re-conditioned item. A reconditioned item is about one third the price of a new item. There are 2 types of PCB available. The 'original' has a reset button that sits behind a membrane (see Fig.4a) where as the 'revised' item has a reset button that projects through the front control panel (see Fig.4b). If you have an original item most suppliers of the revised board include a new fascia to accomodate the new reset button.

See our links page for a selection of suppliers.

Note: prices for new items vary considerably and stocks can be limited as the board is a 'bestseller'.

Replacing the PCB

Remove screw A (Fig 1) and pull the side cover forwards to remove.
Remove screw B (Fig 2) and the PCB casing 'should' hinge forward to reveal the PCB. I say should because in some cases the installer will not have fit this properly on the hinge, as was the case with my installation.
Don't be too worried about all the wiring connectors as each plug will only fit on the appropriate connector, unless forced!! The exceptions are the connections marked C and D in Fig 3.
Undo all the wiring connections.
Remove the four screws (marked E in fig 3) securing the PCB to the housing.
If you are replacing an 'original' item with a 'revised' item you will need to replace the stick-on fascia that was supplied with the new board.
Fit the new PCB using the four screws removed in step 5 and reconnect all the wiring, taking care not to apply too much force to the PCB itself.
Re-fit the side cover following the reverse of the removal procedure.

Please click on an image if you would like to see a higher resolution image.

Fig 1	Fig 2
Fig 3	Fig 4a Fig 4b

Electrode lead
(part number 8407753)

We have been informed that this does not apply to the Suprima 120

The red electrode lead that feeds the ignition switch can have a shortened insulation that causes a short that results in the boiler not firing up. This is evident when the boiler is cold you see that the boiler will attempt to start 3 times before resorting to flashing it's red light at you.

The best solution is to replace the lead at an approx. cost of £3.00. It is not advised to cover the gap with insulation tape or similar due to the heat involved. Note that in Fig 6 a temporary fix has been applied and the 'burning' of the flex insulation used is quite evident after only one week.

To replace this lead remove the boiler side cover (steps 1 and 2 for replacing the PCB) then remove the 2 screws marked H in Fig 5 and open the front cover. The connections are shown in Fig 6 and Fig 3 (marked D).

Fig 5

Fig 6