BAXI gas boiler {confusion}

MrAbc

Hi all,

We have a nice new gas boiler: BAXI Megaflo System 15 HE IE, a condensing boiler not a combi boiler...

Anyways, the installer(who it turns out was fairly inexperienced, recommendations bedamned ) says that there should be no power to the boiler when the timer(an external wall-mounted one) is not calling for heating.
However, inspector who came to check his work says there should be power so that an error code stays on the display, should one occur, even though the boiler would cut off due to the error.

[Currently, the timer cuts off total power to the boiler. EG With timed heating for say 2-hours on, 2-hours off, etc, each OFF period cuts off all power to the boiler. Any error code would be lost, it seems... over-heating, over-pressure, etc, only for it to re-occur at the next ON period!!] and that the installer should fix this.

Installer says inspector is confusing this (condensing) boiler with similar-looking BAXI combi boilers which do need constant power, even with timer not calling for heat. He says the supplier and manufacturer have been phoned for info and that this no-power situation is exactly correct.

{confused :-(}

Is this correct? Can the inspector be that clueless? Do only combi boilers work like that?

And if the installer is correct, what good are error codes?? Isn't it dangerous for the boiler to repeatedly over-heat or over-pressure, let's say??!! And you'd never know unless you look at the boiler just after it happens!!

Cheers for any ideas.

Your installer is talking out of his back side, the wiring requirement is the same be it combi or system and it being condensing has even less impact on determining the wiring requirements, and if you want to put manors on him ask him how he proposes the boiler dissipates heat when the power is cut and how the frost protection will work without a permanent feed to the boiler as it would require one to fire, below is the statement from the manufactures instructions for your boiler:

1. The frost protection mode is integral to the appliance and

functions when the selector switch (see Section 2.1) is in the

ON position ( ). If the system temperature falls below
5° C then the boiler will fire on its minimum setting until a flow temperature of 30° C is reached. Further protection
can be incorporated by using a system frost thermostat

To keep things simple as the instructions say:

The boiler is fitted with a 1.3m length of 3 core of cable.
This can be connected to the fused 3A 230V 50HZ supply

this means the power to the boiler would come via a fused switch within arms reach of the boiler or a plug in a socket within arms reach of the boiler, any external controls(clock, programmer) of any kind must be wired on the boiler control board again in the fitting instructions:

6. Remove the link between terminals 1 & 2. The switched

output from the external control must be connected terminal 1.

The way it's wired at the moment gives a get out for the manufactures for any warranty claims and could effect a house insurance claim god forbid if ever you had to make one, i say that as a manufactures technician, if you download a copy of the manufactures instruction which will have the only way to wire your boiler, anything else is unacceptable http://www.baxi.co.uk/docs/Baxi_Megaflo_System_HE_Installation_Instructions.pdf also give them a ring yourself just so you know where you stand, Gary

MrAbc

Great to get proper advice on that. Thanks Gary.


Their lack of certainty gives us the willies tbh. I don't want to be wronging the lads, obviously, but... just so I have a clear point in my head, is it possible (without putting yourself into any big mission) from what you've seen in the installation guide(or would BAXI be best asked), for you to say:

for such purposes as the frost protection function and (maybe adding here) reporting error codes that, with the main selector at ON, the display should be illuminated at all times regardless of whether the timer is at an ON or OFF period.

[now given, in case I'm not crediting proper work, that currently the temp. display does light all during each timer ON period whereby the burner fires up intermittently as req. by the thermostat setting. Then the display shuts off during each timer OFF period.]

Might the frost protection, for instance, just normally work with no display active?

[Or is that too simple-minded an approach?... I'm guessing maybe you might want to be looking at/testing what's connected to what.]

Forgive the idiot-speak but getting your head around what is happening/should happen/shouldn't happen is frought with miscalculations and alarmism and the suggestion of talking direct to BAXI is prob a very good idea, will try that too anyway.

Thanks again for the insight though.

In a ideal world the power for the boiler will come from a switchable fused spur straight to the boiler giving a permanent supply to the boiler with any external timer switching happening after the power has hit the boiler control board, you may find with the boiler front control setting in the off position that the display wouldn't light, so the display lighting may not be the best way to determine the correct wiring on the boiler, the power can not first go via a timer/programmer because if the boiler needs to fire for self protection, say if there was snow on the ground and the boiler had no power then it couldn't fire risking damage and no insurance/manufacture would stand by your installation, also your boiler will not dissipate heat correctly from the heat exchanger when the power is cut and this can lead to problems in the future and again the manufactures could instruct you to rectify wiring before any repairs are done, most installations i go to are wired like yours so you are not alone, Gary.

It's not my opinion, your opinion, installers opinion or the inspectors opinion that counts, it must be as per the manufactures instructions.