New Worchester 15i intermittently wont work

[Raff]

Hi I have recently had a Worchester 15i Regular boiler installed, it comes with honeywell control and thermostat also. Its suddenly developed a very odd random intermittent problem.

I can set thermostat to 30c (house temp is 20c), set my honeywell control HotWater or CentralHeating to On (Cont), green light goes on and Boiler has zero response in
coming on, no white flame logo on the boiler or firing up, radiators cold and no hot water. Other times it works fine though and comes on fine for both.

Only work around I have found is when this "glitch" occurs, I can press the power off button for 30 minutes and this resets the boiler, then when I press Cont or ON it fires up and works fine.

Its like my Boiler is drunk while on the job and other times sober.

Company and engineer that helped install it are fantastic however, he can only fix a fault he can see and since this fault occurs so random that when he checked it recently it was naturally working fine, so I am stuck somewhat here. Does anyone have any idea what it could be fault wise ?

I should add no fault codes or anything appear on the boiler or honeywell controller, and pressure has been checked and is fine so has the hw cylinder by company.

 

[Chuck]

The boiler has an oval blue light on the front of it. This shows when the boiler is receiving a 'call for heat' signal from the controls. How doe this behave when your glitch occurs?

What type (i.e. model numbers) of Honeywell controls do you have? In particular are they wireless?

 

[Raff]

The boiler has an oval blue light on the front of it. This shows when the boiler is receiving a 'call for heat' signal from the controls. How doe this behave when your glitch occurs?

What type (i.e. model numbers) of Honeywell controls do you have? In particular are they wireless?

hi thanks for reply, I got the boiler model wrong its an Greenstar GR4700iWS with a honeywell ST9400c controller.

I could not see any blue oval light on the front of it, but yes when I press cont/on the green light goes on, boiler is basically showing no white flame logo, its lights are off but I can hit ok button and it pops up with the worcester colour logo display, menu can be accessed fine.

So no lights at all even after 30 minutes, with thermostat on 30 (house is 20c).

I understand the boiler sometimes wont come on right away and it sometimes takes 5-10 mins, but there are times when it just wont come on for hours and other times it behaves fine and works.

A very weird issue, one that had the boiler engineer puzzled.

 

[Deleted member 120897]

I sounds like a motorised valve fault or wiring fault. What valve(s) do you have?

 

[Raff]

I sounds like a motorised valve fault or wiring fault. What valve(s) do you have?

Not sure about the valves to be honest, I just saw a vid on how to get to engineers menu and check status so ill do this when the fault next occurs, its tricky since most of the time its behaving normal and working, its a bit odd it works 6-7 times out of 10, but just those 3-4 times sometimes it wont respond and work, very random.

 

[Deleted member 120897]

You could post a photo of airing cupboard, we can then tell you what valves you have.

 

[Chuck]

Not sure about the valves to be honest, I just saw a vid on how to get to engineers menu and check status so ill do this when the fault next occurs, its tricky since most of the time its behaving normal and working, its a bit odd it works 6-7 times out of 10, but just those 3-4 times sometimes it wont respond and work, very random.

My guess is a flakey microswitch on a zone valve or a loose / badly made connection.

I strongly suggest you stay out of the "engineer's menus", you can potentially do damage in there if you don't know what you are doing. I haven't checked your model but for many WB boilers there is an 'info' button which is safe (i.e. you can't accidentally reset important parameters) and display the boiler state.

 

[Raff]

thanks undertrained here are some pics of the airing cupboard and boiler:

airing-cupboard

Image airing-cupboard in Patman's images album

ibb.co

close-up-airing-cupboard

Image close-up-airing-cupboard in Patman's images album

ibb.co

worcester-boiler

Image worcester-boiler in Patman's images album

ibb.co

worcester-top-of-boiler

Image worcester-top-of-boiler in Patman's images album

ibb.co

Boiler has been behaving fine today, otherwise I was planning on doing a video recording to show the odd glitch or when it fails to actually fire up and start.

 

[Raff]

My guess is a flakey microswitch on a zone valve or a loose / badly made connection.

I strongly suggest you stay out of the "engineer's menus", you can potentially do damage in there if you don't know what you are doing. I haven't checked your model but for many WB boilers there is an 'info' button which is safe (i.e. you can't accidentally reset important parameters) and display the boiler state.

thanks I will keep this info of microswitch zone valve, the other installer did say its possible its a valve issue, but didn't say which type during his quick inspection.

Ok I think ill stay out of there as much as possible, I was careful to not change or alter settings but did spot there was a current status option which showed call for heat message so was going to check that the next time it doesn't go on, also a reset to factory setting is there, which is what the installer suggested I do if I have an issue rather then switching the main power off for 30 mins to fix the issue, he advised that does more harm then good directly switching it off like that.

 

[Deleted member 120897]

Wow that 3 port valve is close to the cylinder 😱😱 this may be the cause of your problem.

 

[Raff]

Here is a link to a video I took this morning showing the exact issue.

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I waited for over an hour and suddenly it just came on and started to work.

So do you think its the 3 port valve or microswitch zone valve that could be at fault ?

 

[Deleted member 120897]

Sorry, unable to playback video. I’d say the 3 port is at fault yes.

 

[Raff]

Sorry, unable to playback video. I’d say the 3 port is at fault yes.

thx, try refreshing this page, I added a youtube video link.

or here :

 

[Deleted member 120897]

Yep, still seems like the heating is only coming on when hot water is calling. Try turning up the cylinder thermostat and see if heating kicks in - if it does then you’ve found your fault.

 

[Raff]

Yep, still seems like the heating is only coming on when hot water is calling. Try turning up the cylinder thermostat and see if heating kicks in - if it does then you’ve found your fault.

Is this the cylinder thermostat ? Its set to 60c at the moment, so next time this glitch fault happens I should try 70c or 80c and see if it forces the boiler on ?

 

[Deleted member 120897]

View attachment 65711

Is this the cylinder thermostat ? Its set to 60c at the moment, so next time this glitch fault happens I should try 70c or 80c and see if it forces the boiler on ?

Yes that’s the one, yes try it at either, or if you next go to put the heating on and the glitch happens, put the hot water on as well and see if that brings heating on.

 

[Raff]

Yes that’s the one, yes try it at either, or if you next go to put the heating on and the glitch happens, put the hot water on as well and see if that brings heating on.

Glitch did occur again, I did try putting hotwater and ch on at same time but no joy, however I did increase the cylinder to 80c and that did bring the boiler to kick in !

Thanks, at least I have a temporary fix to stay warm

 

[Deleted member 120897]

Definitely say it’s the 3 port, make sure it is only temporary. 80 degrees water is very hot and produces scale.

 

[Raff]

Definitely say it’s the 3 port, make sure it is only temporary. 80 degrees water is very hot and produces scale.

thanks will do, I actually put it to 80c and then by the time I got downstairs the boilers kicked in with the white flame logo, so just go back upstairs and put it back to 60c, it still seems to stay on just fine and works on the next timer also.

 

[Raff]

Definitely say it’s the 3 port, make sure it is only temporary. 80 degrees water is very hot and produces scale.

Just wanted to say thanks to yourself and others, they did fix the issue the chap said it was the wiring near the 3 port that was incorrectly wired, he left it thinking it was wired correctly during the new installation so no need to adjust it but on 2nd looking it was wired wrong, so corrected it.

Set to default 60c, boiler now comes on properly 1st time after a month so I know its good. Company did a good job sorting it out at least.