Worcester Bosch 40CDI Regular Boiler Fault Please Help!

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just had a look at your pictures, nice to see decent sized pump and pipework, all I can suggest is bringing down the boiler output and see if it diminishes the lockouts, press and hold the spanner symbol for ten seconds and find out what the boiler output has been set at.
 
1a comes up. We are having the pump replaced again tomorrow incase it's a blockage, the water works without the heating and the guy who looked at it said he thought the pump was making a different noise.
 
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old thread I know, but this is the EXACT situation I've had on and off for a while.

did you ever find a solution?

fault code is the same when I go through the 1a->6a and press the button with the little chap with the hat on button (how weird is that!) and it says E9 which is overheat which equals flow problem. I know this.

but I've done the usual of draining down, removing air locks, pump was changed 2 years ago

I'm in the middle of moving the HWC anyway so the new f/r will be in 28mm and the route is significantly simplified so any old flow problems should disappear.

just curious in the meantime if there is any answer to this I've overlooked?

for example, is it possible for me to reduce the power of the boiler (its a Worcester 40CDI too)
 
POSSIBLE SOLUTION **** POSSIBLE SOLUTION **** POSSIBLE SOLUTION ****

for anyone who is searching for the SOLUTION to this issue (and I know from posts on many forums that this is an issue that effects a number of people), I just wanted to state here what one possible SOLUTION is

I had a great Worcester Bosch engineer out this weekend who quickly diagnosed the issues and resolved it by replacing the circuit board. boiler now working as new, no issues whatsoever, lovely hot water and heating!

My advice: if you have this problem, or any similarly frustrating problem, give Worcester a call directly.

there is no way I could have ever solved this issue and advice I'd had ranged from re-plumbing the entire system, powerflush, changing the pump, changing the zone valves, changing the heat exchanger, changing the HWC - the list goes on and none of them were correct. (which to be fair, isn't that surprising as at least some of those people hadn't ever looked at the system, so unfair to expect a correct diagnostic - I'm merely saying that perhaps you don't just jump to a quick, say, pump change and hope it fixes the issue)

NOTE: I do not work for or have any relationship with anyone who works for Worcester Bosch whatsoever
 
i have heard of this and what happens is software on the pcb notices when temps rise or fall too fast and it blocks out the burner and hovers between 45degrees to 53 or 54. Usually happens in large properties where there is large cylinders/underfloor heating. I've been told that they can fit a new pcb which hasn't got this software on. Is this what is happening to yours?? If they changed heat ex then i imagine it is not and it is overheating!(which could well be your system/setup!)

If its in warranty still maybe see if worcester will send out a senior tech engineer to have a look! Their diagnostics are very good at watching temp rises etc!

hope this helps!


If only you had bothered to read all of this thread you would have seen that this was explained five years to the original poster!

Tony
 
oh dear, what a sad response.

What I posted was to "back up" one possible solution and to confirm it fixed the issue for me

Responses, negative ones like yours, trying to be clever attacking people for 'not bothering to read stuff' are the reason I and many others I've spoken to have left this forum.

So go nuts replying, I won't see it as I've unfollowed this thread. I only wanted to complete this particular issue to help some othe guy when he Googles for this problem.

Happy New Year.....
 
POSSIBLE SOLUTION **** POSSIBLE SOLUTION **** POSSIBLE SOLUTION ****

for anyone who is searching for the SOLUTION to this issue (and I know from posts on many forums that this is an issue that effects a number of people), I just wanted to state here what one possible SOLUTION is

I had a great Worcester Bosch engineer out this weekend who quickly diagnosed the issues and resolved it by replacing the circuit board. boiler now working as new, no issues whatsoever, lovely hot water and heating!

My advice: if you have this problem, or any similarly frustrating problem, give Worcester a call directly.

there is no way I could have ever solved this issue and advice I'd had ranged from re-plumbing the entire system, powerflush, changing the pump, changing the zone valves, changing the heat exchanger, changing the HWC - the list goes on and none of them were correct. (which to be fair, isn't that surprising as at least some of those people hadn't ever looked at the system, so unfair to expect a correct diagnostic - I'm merely saying that perhaps you don't just jump to a quick, say, pump change and hope it fixes the issue)

NOTE: I do not work for or have any relationship with anyone who works for Worcester Bosch whatsoever

I know this thread has been running for a few years but I felt it was worth sharing my own experiences:

I have a Worcester Bosch 40 CDI Regular boiler which was installed 8 years ago in 2010. I had this same problem recently with the boiler service manual indicating "
The gradient limitation is active. The primary temperature is rising too fast and the burner has switched off for 2 minutes. See error E9."

I spent some considerable time and effort checking out the water flow, replaced the pump and had the boiler serviced by a certified Worcester Bosch engineer. On my own initiative I then approached Worcester Bosch for a solution and they suggested replacement of the boiler PCB. I was able to source this at a reasonable cost (<£50)and the replacement was fitted in 15 - 20 minutes. Problem solved.

It was only after this that I found this thread which I wished I has found earlier. What makes me particularly angry is that Worcester Bosch, it's agents and an experienced plumber were not able to solve this themselves. The service booklet for engineers has errors in the E9 rectification process. It is possible that I had the problem to some degree from when the boiler was installed. The solution was I believe an upgrade in the PCB firmware and should have been made available by Worcester Bosch as a fix under warranty or at least circulated to their agents as a known problem and an exchange process put in place to obtain an updated PCB.
 
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Have a look at headloss diagram in the manual, understand pump curves and index circuits and all will become clear. I suspect the pcb is just a bodge by Worcester to make the software more tolerant of large temperature drops across the heat exchanger. Suficient flowrates are the key.
 
I know this thread has been running for a few years but I felt it was worth sharing my own experiences:

I have a Worcester Bosch 40 CDI Regular boiler which was installed 8 years ago in 2010. I had this same problem recently with the boiler service manual indicating "
The gradient limitation is active. The primary temperature is rising too fast and the burner has switched off for 2 minutes. See error E9."

I spent some considerable time and effort checking out the water flow, replaced the pump and had the boiler serviced by a certified Worcester Bosch engineer. On my own initiative I then approached Worcester Bosch for a solution and they suggested replacement of the boiler PCB. I was able to source this at a reasonable cost (<£50)and the replacement was fitted in 15 - 20 minutes. Problem solved.

It was only after this that I found this thread which I wished I has found earlier. What makes me particularly angry is that Worcester Bosch, it's agents and an experienced plumber were not able to solve this themselves. The service booklet for engineers has errors in the E9 rectification process. It is possible that I had the problem to some degree from when the boiler was installed. The solution was I believe an upgrade in the PCB firmware and should have been made available by Worcester Bosch as a fix under warranty or at least circulated to their agents as a known problem and an exchange process put in place to obtain an updated PCB.

So you are “angry with Worcester Bosch “ you checked out the water, changed the pump, then you got out an installer to service the boiler. Then you got a cheap pcb ( maybe recycled ) and either you fitted it or someone else did. This is the point that you rang wb and they told you pcb???? Yet your angry !!! After a phone call about an 8 year old boiler and they give you a correct diagnosis on the phone, and your angry

If you had phoned wb at the outset of your problem and asked for a visit it would have been fixed next day, but no, you know best and do your own investigations that probably dragged on for months.

I imagine you are an ex engineer in a different field and are actually angry because you couldn’t nail the problem yourself and it cost you a couple of hundred quid to play expert with your boiler.
 
Well done boilerdoctor almost 100% correct except the PCB was brand new. I also failed to say that the problem was intermittent and 9 times out of 10 the boiler fired up to full temperature correctly.

However my point is that if I had found theSouth's post sooner I would have found the solution a lot sooner. This solution should have been forthcoming from Worcester Bosch and/or its agents. I should not have to resort to the web to find a solution and advise my plumber/boiler engineer how to fix the problem.

My advice is the same as theSouth's "if you have this problem, or any similarly frustrating problem, give Worcester a call directly and refer to this stream." It takes no time at all to check the pcb software version.
 
Well done boilerdoctor almost 100% correct except the PCB was brand new. I also failed to say that the problem was intermittent and 9 times out of 10 the boiler fired up to full temperature correctly.

However my point is that if I had found theSouth's post sooner I would have found the solution a lot sooner. This solution should have been forthcoming from Worcester Bosch and/or its agents. I should not have to resort to the web to find a solution and advise my plumber/boiler engineer how to fix the problem.

My advice is the same as theSouth's "if you have this problem, or any similarly frustrating problem, give Worcester a call directly and refer to this stream." It takes no time at all to check the pcb software version.


Hate to say I told you so, but I put the original answer on here.

Viva Worcester bosch

I’m always around if you need help, I’m a wb engineer
 
It was your original post and theSouth's which helped me solve this problem. Thank you.
 
I know this thread has been running for a few years but I felt it was worth sharing my own experiences:

I have a Worcester Bosch 40 CDI Regular boiler which was installed 8 years ago in 2010. I had this same problem recently with the boiler service manual indicating "
The gradient limitation is active. The primary temperature is rising too fast and the burner has switched off for 2 minutes. See error E9."

I spent some considerable time and effort checking out the water flow, replaced the pump and had the boiler serviced by a certified Worcester Bosch engineer. On my own initiative I then approached Worcester Bosch for a solution and they suggested replacement of the boiler PCB. I was able to source this at a reasonable cost (<£50)and the replacement was fitted in 15 - 20 minutes. Problem solved.

It was only after this that I found this thread which I wished I has found earlier. What makes me particularly angry is that Worcester Bosch, it's agents and an experienced plumber were not able to solve this themselves. The service booklet for engineers has errors in the E9 rectification process. It is possible that I had the problem to some degree from when the boiler was installed. The solution was I believe an upgrade in the PCB firmware and should have been made available by Worcester Bosch as a fix under warranty or at least circulated to their agents as a known problem and an exchange process put in place to obtain an updated PCB.
Hi. I am having the same problem and wondered if you had any details on the PCB that was replaced? I would like to order one to try but not sure how to get one. Many Thanks.
 

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