Vaillant VSmart and error F28

[icchis]

Hi everyone,

I need help with something going on with my boiler. Last Friday I had an F28 ignition error on my Vaillant EcoTec Plus 832. A reload worked and it was back in operation. On Monday it happened again and it took few reload to make it back to work so I called a plumber that came and cleaned the electrode.

The boiler seemed fine and I decided to do a job that has been postponed for too long, put a shorter and clean cable for the VSmart installed in the boiler.
At that time the boiler kept triggering the F28 error over and over so I decide to replace the electrode. It was fine for one day and then again with the error over and over. I decided to try the boiler without the VSmart connected (I physically unplugged the connector from the board and the boiler started working straight away.

I did all the VSMart cabling again and everything looked fine until the last two days where I had a couple of error again, one at 5:30 in the morning when the temp change for the day (so first start) and the other at the end of the day. During the day it was absolutely fine.

As an experiment I decided to change the VSmart algorithm from Advanced to Hysteresis and reset the heating curve and this morning at 5:30 the boiler started with no issue. It could be coincidental but who knows.

So here's the question to someone more expert than me: is it possible that the VSmart causes an F28 error?

If it happens again I'm gonna try unplugging the VSmart from the board and see what happens. Looking at the list of error in the boiler I can't see any F28 from when the previous owner lived here. The error started after I installed the VSmart in Jan (just 2-3 errors in 2 months since last week)

 

[CBW]

Did you carry out critical gas safety checks after fitting the electrode? Are you gas safe registered/competent?

 

[icchis]

Did you carry out critical gas safety checks after fitting the electrode? Are you gas safe registered/competent?

When I said "I decided to replace the electrode" I mean I let the plumber do the job.

 

[CBW]

Ok, so I wouldn‘t think that a control would cause ignitoon/lack of gas failure. Forum rules forbid gas related advice in an open forum, I would get a different gas engineer or go to Vaillant for fixed price repair. F28 can be anything in the ignition sequence including a blocked or frozen condensate pipe.

 

[Seliaks]

Hi, I had the f28 error code with my boiler back in October, at the time I was also using the vSmart controller. I initially tried a local gas engineer who tried a few things and changed the boiler's gas valve, but after a few days f28 would come back. In the end I bit the bullet and negotiated a deal with Vaillant where for a flat charge of £149 they sent an engineer round who serviced the boiler (again), reinstated my 10 year boiler guarantee and did as much work as was needed.

It took him two goes to sort it. At the first visit he replaced the boiler PCB, put in a new gas valve (again) plus a few other bits, but the f28 fault returned after a few days. At the second visit he replaced some other parts, plus a sensor wire that tells the boiler how high the flame is - he said that it was testing too low in terms of volts or resistance I can't recall - as soon as he'd changed that wire the boiler has worked fine, with no errors since - it must have been a gradually developing intermittent fault. Prior to him replacing the wire, after he'd replaced the PCB, the boiler worked ok, but seemed to have a job holding the flow temp steady. I think that gave him the clue that the sensor wire was not giving the boiler the correct info about the flame power.

I wish that I'd got Vaillant involved from the start - I spent nearly £500 with the other engineer for a service, fault finding and then the new gas valve etc. I had forgotten that I had a 10 year warranty on the boiler, but I hadn't had it serviced in the first 2 years, although I'd had annual services after that (but had very patchy documentation - no one had signed the service record in the boiler manual), so the warranty had lapsed, so it was good they offered to reinstate it for £149.