Worcester 30 CDI Greenstar Pulsating Noise

pg325 · 1 Feb 2012

I had a 30 CDI fitted a few months ago, recently it's been coming on early in the morning as the house temp is dropping, because it's so quiet in the house you can hear the boiler, this is fine but it seems to run for a few minutes then you hear a faint warble or pulsating noise for about 20 seconds, it seems to do this on a constant cycle every few minutes.

I was wondering if it could be the condensation trap purging.

The noise is hardly noticable in the day as it really is that quiet but as I say early in the morning when the house is deadly quiet you can hear it.

Has anyone else noticed a similar noise or any engineers know if these are designed to do this?

pg325 · 1 Feb 2012

Just to be a bit more exact, the noise is only when the boiler is firing as the green flame symbol is alway lit. It's very regular, every 3 ish minutes the pulsating last 34 seconds, I thought maybe it could be the condensation trap emptying but can't feel the plastic waste changing temerature.

It's sounds as if its the pump and after 34 seconds the pulsating stops and you can hear the pump change tone back to normal.

Is this normal for this boiler?

boilerdoktor · 2 Feb 2012

that boiler is very smart, it has an eight speed fully modulating pump so i would expect to hear a difference in pump speeds.

Highmiler · 2 Feb 2012

Hi, this sounds almost the same fault I had with my new 37CDI. Yep, every 3 mins or so a rumbling sound for 30 seconds then back to normal when the CH is on. I cannot offer a solution only my experience with this problem...

5 Engineer visits along with the WB accredited Installer each time (he turned out to be an absolute diamond) All agreed there was a problem.
1st Engineer said it was a 'restriction' in the pipework. Installer fitted a bypass valve FOC. Problem still persisted.
2nd Engineer changed the pump. Problem still persisted.
3rd Engineer changed the PCB. Problem still persisted.
4th Engineer changed the heat exchanger. Problem still persisted.
5th Engineer (along with service manager this time) came armed with a laptop and did a software change to the pump modulation. This cured the problem with the CH. Now it happens only when the HW is running

I've learned to live with it now, resigned to the fact it is what it is. I wanted to carry on fighting for a proper solution instead of what I Feel is a bit of a bodge but I was starting to get a lot of flack taking time after time off work for the visits.
P.S. From my experience with WB... whatever happens you WILL NOT get the boiler replaced.

Kind regards.

pg325 · 2 Feb 2012

Highmiler said:
Hi, this sounds almost the same fault I had with my new 37CDI. Yep, every 3 mins or so a rumbling sound for 30 seconds then back to normal when the CH is on. I cannot offer a solution only my experience with this problem...

5 Engineer visits along with the WB accredited Installer each time (he turned out to be an absolute diamond) All agreed there was a problem.
1st Engineer said it was a 'restriction' in the pipework. Installer fitted a bypass valve FOC. Problem still persisted.
2nd Engineer changed the pump. Problem still persisted.
3rd Engineer changed the PCB. Problem still persisted.
4th Engineer changed the heat exchanger. Problem still persisted.
5th Engineer (along with service manager this time) came armed with a laptop and did a software change to the pump modulation. This cured the problem with the CH. Now it happens only when the HW is running

I've learned to live with it now, resigned to the fact it is what it is. I wanted to carry on fighting for a proper solution instead of what I Feel is a bit of a bodge but I was starting to get a lot of flack taking time after time off work for the visits.
P.S. From my experience with WB... whatever happens you WILL NOT get the boiler replaced.

Kind regards.

Bugger, sounds as if I may need to get them out to look at it afterall, anyone else had this problem with their Worcester?

Highmiler · 3 Feb 2012

I trawled the Net and the Plumbing section here with no joy, could have been down to wrong keywords I guess. From experience - time is of the essence here to get it sorted. I wonder if my case was weakened due to the fact the problem didn't become apparent / reported for around 6 months after installation - I had it installed late spring and didn't really use the CH until it got cold in Autumn, if it got cold in the evening we sparked up the log burner. It was only when we started to use it on the timer in the mornings we used to get our WB 5.30 wake up call (boiler in airing cupboard next to bedroom).
Hope you get a result.

Kind regards.

kimeddie · 19 Jan 2015

Hi all
Few years since the last post but hey .....

I am having the same issue i think with my 28cdi greenstar.
Will let you know how I get on, I did have some rainwater get in the boiler so might be linked to that not sure.

Dill · 13 Mar 2015

kimeddie said:
Hi all
Few years since the last post but hey .....

I am having the same issue i think with my 28cdi greenstar.
Will let you know how I get on, I did have some rainwater get in the boiler so might be linked to that not sure.

Most of these noise issues can be solve by setting the correct pump map.
The normal setting is proportional pressure high which is to high in a lot of cases.
In the first level service function 1c set the pump to 0 so you can manually adjust the pump step in 1d. this goes from 2 - 7 set a low one, say 3 and try it.
Also under 3f you can set the burner off time in DHW mode, reduce this to 10secs. (burner switches off after 10secs), the standard setting is one minute.
Then in the second service level under 9f you can drop the pump overrun time down to 1 min, standard setting 3 mins.
Adjusting the pump speed and overrun will help in the majority of cases of reducing noise where you have motorised valves and bypass valves fitted.

PEDANTICVINDICTIVEMAN · 13 Mar 2015

Failing all that faffing and fannying, rip it out and skip it, then just fit a decent boiler.

diyn24318 · 6 Oct 2019

I am responding to this thread despite its age because there is nothing about "map pump step" on the web and I am keen to try and understand more from this poster.

Dill said:
Most of these noise issues can be solve by setting the correct pump map.
The normal setting is proportional pressure high which is to high in a lot of cases.
In the first level service function 1c set the pump to 0 so you can manually adjust the pump step in 1d. this goes from 2 - 7 set a low one, say 3 and try it.
Also under 3f you can set the burner off time in DHW mode, reduce this to 10secs. (burner switches off after 10secs), the standard setting is one minute.
Then in the second service level under 9f you can drop the pump overrun time down to 1 min, standard setting 3 mins.
Adjusting the pump speed and overrun will help in the majority of cases of reducing noise where you have motorised valves and bypass valves fitted.

Dill, I took your advice and had a look at this on my WB 30 CDi. Can you advise what the individual steps (2 to 7) do, how I would choose one, or more detail on each?

I have wet underfloor heating throughout; what I am trying to do is balance decent heating performance during the day with minimal boiler/water travel noise at night.
I have read a constant pressure map may suit UF better, however the middle constant pressure setting does increase boiler noise noticeably over the low setting.

Am I trying to get the water hottest quickest to the manifolds, or a gradual build up/ongoing supply? (I ask as I understand UF regulates water to c. 30-40 C so would assume the latter and I only need to ensure hot water is supplied at 70C without cycling)

Any other input gratefully received.

NB

diynot

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Worcester 30 CDI Greenstar Pulsating Noise

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