Baxi duotec GA 33 E53

[helplessowner]

1st post here, long time lurker. So I know that you cannot give gas-safe advice on the forum.
Long introduction before I get to the question - sorry.
Background: park home (basically a wooden bungalow) with above boiler installed (yes, I now know it is oversized) 10 years old.
Vertical flue (very short vertical flue).
Condensate pipe drops straight down under the home to join horizontal main waste pipe.
Runs on mains gas (NOT LPG). We have a water softener (also 10 years, also serviced each year).
Serviced every year under Baxi's own (now very expensive) maintenance plan.
Serviced in May, working all OK (electrode and seal replaced as part of service).
Next day, tried hot water - E133, Would not reset.
Since then, Baxi have been out 5 times (all under the service plan).
Tech 1 calibrated, said all OK, but it failed within 20 minutes, first time we turned on a hot tap (E133).
Tech 2 checked condensate pipe (from boiler end) said was clear, adjusted gas/air mix which removed E133, and it worked fine for 8 days, then started making SOMETIMES (not always) extremely strange and worrying rumbling and bangs on ignition before settling down and working quietly.
No error codes.
Hubby went up ladder to look at flue, pluming, no visible signs of any blockage.
Tech 3 managed to replicate the noise but could not find out why. Changed sensor and fan. Checked condensate pipe, said was clear.
Checked flue (from the boiler end) and said was fine.
Calibrated but would not complete (tried 3 times).
On last attempt E53 showed up. Tech said that was not possible, but left it anyway.
Next morning - E53 and lock out.
Tech 4 replaced gas valve and PCB, but turned boiler off as unsafe (not burning properly) while waiting for heat exchanger.
Tech no 6 replaced heat exchanger and was here for a very long time (about 3 hours) recalibrating and checking everything. Left it working very quietly.
That was 8 days ago - and guess what? E53.
It runs on either heating or hot water for about 10-15 minutes, all seems OK. Then flame symbol goes off and shortly after E53 appears on display.
BUT - turn off heating/hot water (whatever was running) E53 clears from display and then immediately turn on hot water and it fires up and runs for another 10 minutes or so before back to E53.
So - Question - finally:
Is it possible for either a flue to be intermittently blocked (one minute it is, next minute it isn't)
Or can E53 mean something else?
Calling Baxi out again tomorrow, but wondering whether to give up and start looking for an installer to replace.
Is this going to be fixable?

 

[Deleted member 267285]

According to a Baxi website, E53 points to the condensate pipe being frozen, but could be blocked?

 

[helplessowner]

Thank you - indeed it does (another Baxi website also says possible combustion error..)
But - IF it is the condensate pipe, 2 techs have checked it and said it is clear, and surely if it was the condensate blocked or very slow draining, then the boiler would not immediately clear the E53 as soon as the heating turned off and the water turned on?
This is what is baffling me (and, it seems, the Baxi techs) - can a blockage in either the flue or condensate pipe be hear one minute (second) and gone the next? Anybody know this?
No criticism to any of the techs who have come out, as they have all been determined to be the one who finds and fixes whatever the problem is - but I am now getting paranoid about whether the boiler will work when we next use it.

 

[gas112]

e53 long shot it could be the actual trap faulty as opposed to the condense pipe to the waste .
one thing to try is remove the actual condense pipe from rubber fitting at bottom of boiler and let it drip into a container see what it does .

 

[helplessowner]

Thanks. We'll certainly ask the next Tech (no 6) to check the condensate trap again - has been checked twice and was OK. Getting the pipe under the boiler to a bucket may be interesting , as - like so many - when the boiler was installed by the home manufacturer most of the pipework is surrounded by cupboards, and there is nowhere underneath to balance a bucket.
Just for the record - Techs 3,4 and 5 had the boiler running full blast for calibrating for 15 minutes or so (Techs 3 and 4 did this 3 times as it would not complete calibration, overheating). Tech 5 ran the boiler after replacing the heat exchanger, and then ran a very long calibration (with all hot taps on), then after calbibration left it running while he packed up all his tools, finished his coffee, and ate the toast we made him - with no errors.
Worked perfectly for several days.
But now we get error 53 after 10 minutes or so, turn off whatever is running, turn on a hot tap and it fires up immediately and runs for another 10 minutes. No funny noises. or odd gurgling sounds, just click -burner off, pump runs, E53.
Sigh. Better stock up the tea, coffee and biscuits.
(I am really not looking forward to the next gas bill, or the next water bill (on a meter).)
The irritating thing is - everything was fine until it was serviced. (yes, I know it is just co-incidence - it happens).

 

[helplessowner]

Just an update - Baxi came out today, I asked about the condensate trap (as suggested - thanks gas112) and after all the recalibrating and adjusting he took it out, it was extremely gunged up. Nice and clean now, though.
So it may have been the cause of E53.
Please keep fingers crossed for me that this is the final visit until the next annual service..........

 

[Deleted member 267285]

Just an update - Baxi came out today, I asked about the condensate trap (as suggested - thanks gas112) and after all the recalibrating and adjusting he took it out, it was extremely gunged up. Nice and clean now, though.
So it may have been the cause of E53.
Please keep fingers crossed for me that this is the final visit until the next annual service..........

Hopefully it’s sorted then. Good on you for the perseverance with Baxi.

 

[helplessowner]

Spoke too soon ... Baxi Tech no 6 came out Monday 3rd. Left it working. Same fault back today - E53. But turn off whatever is running and it clears itself - which Tech 6 said should not happen.
Tech 7 booked for Tuesday (luckily, we have a maintenance plan with Baxi...).
Interesting, Tech 2 said the gas/air mix was wildly out. Tech 4 said plenty of gas. Tech 6 said not enough gas.
Something is not right (so far replaced gas valve, PCB, a sensor (no idea which) and various seals. Oh, and the heat exchanger - which certainly made a difference, now runs very quietly and produces hot water faster.
If ANYONE has any ideas to suggest to Tech no 7, would appreciate it as we are getting somewhat emotional now.
We just want our gas boiler working.

 

[Deleted member 267285]

Tbf I don’t think it should have got this far, without some form of senior engineer attending. @gas112 is the usual Baxi man on here. Has the condensate pipe been inspected along its entire length, where possible?

 

[helplessowner]

Thank you.
According to Baxi, 2 of the Techs sent out are senior techs. Not sure how senior.
So far, nobody has been able to pinpoint any specific cause.
The condensate has only been checked at the boiler end (Twice, both Techs said it was OK).
The pipe runs vertically straight from the boiler through the floor to the main horizontal waste pipe under the home (it is a Park home, so effectly a bungalow on stands). This is, apparently, standard fitting for park homes.
There is not an external air-break or trap.
Unlikely that Baxi will go under the home, so we'll book one of our local independents to come out and have a look - and give any other suggestions they can think of.

 

[helplessowner]

Just to update if anyone is interested. Baxi visit no 7, this time a senior-senior tech.
As luck would have it. E53 came up while he was checking it, which helped - very difficult when all the Tech have to work on is our description.
Turned out to be a slightly pinched PCB wire to the fan.
The condensate pipe was not the problem - but it has developed a bit of a weep at some joints, so our local independent will be fixing that.
Hopefully, this will be the end of it - if the error comes up again then the whole thing goes away.

 

[gas112]

Just to update if anyone is interested. Baxi visit no 7, this time a senior-senior tech.
As luck would have it. E53 came up while he was checking it, which helped - very difficult when all the Tech have to work on is our description.
Turned out to be a slightly pinched PCB wire to the fan.
The condensate pipe was not the problem - but it has developed a bit of a weep at some joints, so our local independent will be fixing that.
Hopefully, this will be the end of it - if the error comes up again then the whole thing goes away.

Let us know how visit number 8 goes

 

[helplessowner]

Oooh - cynical.
There won't be a visit no 8 - local independent is on standby, one more error this one gets ripped out and replaced with whatever the installer suggests.

 

[gas112]

The GA was a bit of a pig in the poke from day one they didn't quite get it right. I would not think any pinched cable would cause that error. I would be checking condense entire route and as its a static I would be under building disconnecting it right from where it branches in to waste and further if its on a leg . But it is a strange fault for this time of year with minimal condense being produced .

 

[helplessowner]

Oh, cheers... and there we were all optimistic about the fix.......
Our local independent will be redoing the condensate when he has time (and if the thing continues working, he'll be servicing it as well - we won't bother renewing the maintenance plan)(what's the point of a maintenance plan that does not include anything to do with the condensate pipe? Not even checking it?)

The pipe is a straight drop from the boiler to the main horizontal waste pipe under the home. I know that our local is unhappy about no external air gap, although Baxi instructions say it does not need one, so he intends to put one in during the process.

The Baxi tech explained that it was a wire from the PCB to the fan that was affecting the fan speed reduction (that was the gist) which would explain why the fault, when it happened, was when the boiler tried to modulate down. A lot of wires stripped, inspected and replaced, another PCB, another thermostat sensor, and this time the recalibration worked exactly as it should instead of getting stuck in a never ending overheating loop.
So we'll see.
If it stays working, we're all good. If it does not stay working, new boiler as selected by local independent. So when he does the condensate, we'll be asking for it to be future proofed.
As yet, unable to say yea or nay - too hot to put the heating on, hot water taps have worked all along as they are not on for long, shower later will be a potential test.
Fingers crossed for us, please.