WB Greenstar 18Ri keeps locking out.

[Uncle Buck]

Hi all

I have a 12 year old WB Greenstar 18Ri boiler which has been serviced by the installer annually. It’s been flushed many times and has always had either Fernox or Sentinel X100 in it. A Salus filter was fitted about 2 ½ years ago.

It’s developed a problem where it would lockout at first firing with the blue light flashing, so nice cold house in the morning! It reset okay, but had to run with the boiler stat lower. My installer came and changed the pump – still same problem. He then came back and changed the three sensors: High Limit Stat, Overheat stat and Temp Stat. - still same issue. Checked flue for blockages and gas valve – all okay.

I’ve run Sentinel X800 for a week with no difference, so don’t think it’s a blockage or sludge? The boiler flow and return pipes sit at the same temp, so not convinced it’s the heat exchanger?

Long story short, it runs perfectly with the boiler stat at what I would say = 1 o-clock position. When the system is hot, I can push that to 2 o-clock, but 3 o-clock will cause lockout within 1 minute and the blue light flashing ON to OFF.

What concerned me was when I looked on ‘youtube’ it would appear that my installer never stripped out and cleaned the burner/heat exchanger in 12 years! Could this be my problem?

 

[Gasguru]

If he really hasn't pulled out the burner and baffles in all that time then he's been ripping you off and you should find someone else. After 12 years I'd expect the burner gasket to be toast and the lower baffle to be stuck in there. It'll need a new set of electrodes, bearing plate, trap clean and a thorough hex clean out if the baffle can be removed. I'd get someone new in to have a look at it. Then there's the issue of the lockout.

 

[Uncle Buck]

Thanks for your advice Gasguru.
I'm in the catch 22 situation: do I throw some more money at it and have the burner sorted and then see if the lockouts still occur, or, call it a day and replace it? I know that's up to me, the boiler is in mint condition, but also any major part replacement will make it uneconomic for a 12 year old boiler. Decisions, decisions.

 

[Hot&Cold]

Uncle Buck,maybe consider a worcester fixed price repair

There are not bad boilers but like most modern boilers need a clean system to prevent local overheat and the heat exchanger internals actually need to be serviced/cleaned
i imagine your long serving boiler tech will has already done this operation,some special tools are available to make life easier. See Worcester bosch technical bulletin TB0080

 

[Uncle Buck]

Hi Hot & Cold.
I think a fixed price WB repair is about £350.00, new boiler about £800.00 and this one is 12 years old, so could be uneconomic as I don't know the life expectancy of these boxes. I would get another one, as I also think they are not bad.
The system is pretty clean and always had inhibitor in it, the Salus filter has been in nearly 3 years and trapped a fair bit of muck. It's also been running X800 for a week, with no change to the problem.

My boiler guy is a WB accredited tech, I'm not knocking him really, he's been in the trade a long time, but I'm just surprised that he hasn't stripped out the burner, I know this because we always chat while he works and I would know if he had done it. My thought is that if the burner is clogged up, maybe hot spots are causing the lockouts. I don't know what symptoms to expect with a dirty heat exchanger?

 

[Gasguru]

WB acreditation means zero...I know a local installer that fitted a Worcester in a kitchen larder so high up the outer case could not be removed.
He was politely asked by Gas-Safe to come back and move it ...was I popular

You should be looking for a 10 to 20 degree drop across the boiler. Check to see if the pumps wired to the boiler.

 

[Uncle Buck]

If WB accreditation means nothing, it really makes it a lottery to find a competent engineer!
I'm assuming the pump is wired to the boiler correctly, as it always runs on to take the latent heat out of the system on shutdown.

 

[ianmcd]

you shouldnt leave X800 in your system for a week, flush it out or you will need another new pump

 

[Uncle Buck]

I was going to flush it out this weekend, but it snowed! I'll do it tomorrow and put some X100 in.
I had the cover off this morning for a closer inspection (all isolated) and guess what, the burner gasket is perished - see .jpg. It has damaged the electrode cables and insulation's. No wonder the poor old boiler is struggling, all down to ultra sh1t servicing.

I'm trying to get another engineer in to put this all right. Gasguru is correct, my original guy was ripping me off big time.
I'll post again when it's all fixed with an update. Thanks for everyone's help and advice.

 

[Uncle Buck]

Ok folks, update quicker then expected.

Got WB out on a fixed price repair £275.00 all in. They came out really quickly and replaced the Heat Cell and ancillary parts: as it had just blown the board fuse and was now dead, the fan was replaced as well. This was caused by the heat cell red gasket failure and moisture getting into the motor. Proper job done by excellent WB engineer and all problems due to appalling service (or lack of) by "accredited" engineer.

I can't speak highly enough about WB service, they are supplied with a full van stock, so enabling first fix nearly every time. I will only use WB engineers in future.

I hope my experience helps others?

 

[ollski]

To be fair if your fan speed test was in the acceptable range there is no need to clean out the heat exchanger.

 

[Uncle Buck]

Also, to be fair ollski, there is a thing called "visual inspection" which is a major part of any servicing.
I have been in engineering 48 years and the last 35 in service - this is not rocket science. If just one service was done according to the WB Manual, all this could have been avoided.

Also just to enhance the quality of WB service, I am getting an Audit of the work done as they asked me if I would agree to this, that's the how good they are. Just in case you're wondering, I don't work for WB, but would get another one in a heartbeat.