Baxi Duo Tec 28 HE

[alanrudd]

Can anyone help, i have a Baxi combi boiler, we are getting hot water through the tap, but when we turn the heating on, it clicks a couple of times and then displays a error code of E168 can any body help, or point me in the right direction.

[plumbbob]

Error code E168 is displayed when the boiler has detected a problem but can't work out exactly what it is.

Now, that doesn't help much as it is too vague to be of use.

As the boiler provides hot water ok, then obviously we can cross off most of the possibilities. There isn't a lot left to go wrong, but it is guesswork to point a finger at anything specific. One thing, it may be a flow problem. If the system has been drained and refilled recently and the heating not run since it could be airlocked.

[alanrudd]

Thank you plumbbob.

now what, if it is airlocked ? how do i un-airlock it, yes it has been off a while, but while the heating has been off we have always had hot water.

[alanrudd]

Does the rads have to be bled to free the airlock, or is there some where on the combi system that you need to open, wife is starting to feel the cold, we had someone come out last year and try to fix it, obviously he didnt.

[plumbbob]

Bleeding the rads won't clear a blockage if this is what the problem is. Any airlock that would cause the boiler to shut down will be significant and it is difficult to explain what to look for or how to remove it. Anyway, an airlock should only happen if the system has been drained since last used.

A stuck diverter may also be the responsible culprit.

Has the boiler shown a different error code? Code E168 isn't actually the fault code for the problem, but the response to an earlier fault. It is an indication that the boiler was re-set, after an earlier problem.

Re-set the boiler then run the hot tap and let the boiler settle with hot water flowing. When you are convinced the boiler running happily, with the hot tap still on, switch on the heating whilst constantly watch the boiler display to see what it does.

Incidentally, what is the system pressure?

[htg engineer]

Not sure where Plumbbob is getting info from, if it was a blockage/circulation fault, then you would get E125 or E110 foe overheat/pump issue. E168 is PCB fault, can be other faults causing PCB to play up like fan not getting up to speed, but then you'd get E160 at times too, but 9 times out of 10 - E168 it is the PCB .

htg

[plumbbob]

The point is E168 is not an identifier of an problem but simply an indicator that the boiler has re-set after an earlier fault and that fault cannot be identified internally.

Alanrudd has stated that the boiler works fine during dhw production so many of the faults such as fan speed and so on can be discounted. Because the boiler combustion side is working, even a PCB fault although not impossible, begins to look less likely . What we shouldn't forget is the boiler would be showing a different error code at the beginning before ending up with E168, but of course we don't know what that was. It could have been E125. Logic suggests crossing off the simple possibilities first.

[wshelley]

Hi Alan, did you find out what the cause of this problem was? I'm experiencing exactly the same problem. Hot water is fine, but when I turn the central heating on it cuts out. I get e168 too. I set up a webcam on the display to see if any error code preceded the e168 code and there wasn't any other codes. It just cuts out and goes straight to e168.

If I reset the boiler, hot water works fine again. Central heating may or may not cut out again as it seems to be an intermittent problem. The problem seems to be increasing in frequency now!

Cheers
Wayne