Greenstar 30 CDI - No hot water

[Optimusfb]

Hi guys


The green light no longer appears on as a consequence we aren't receiving any hot water at all!!! Highly frustrating

Does anyone have any ideas what the problem could be?

I have taken a picture of the boiler and the thermostat (this is for putting on the central heating or hot water on). When we do put either one on, that's when the green light appears.

 

[HootingOwl]

Does it fire up for central heating?

What happens if you turn off the ECO mode?

 

[muggles]

OK, I've read your post three times now and concluded that it's largely gibberish. Try to be more descriptive, starting with which green light you're talking about

 

[Optimusfb]

Muggles! Apologies old chum, the green light that indicates that the burner is on. This light normally appears on when i put the hot water on by the thermostat. Separately I notice when I chose to put the heating on the light does appear on.

I just put the eco button on to see if it helps the situation in any shape or form....and it doesn't. It is normally off.

 

[muggles]

OK, I think I understand you - you're saying that when you turn the hot water on on the programmer, nothing happens? If so, go into the user settings and turn the backlight off. If that works, your Honeywell ST9400C programmer is most likely part of a dodgy batch that had rubbish relays on the PCB. Honeywell should honour the warranty as it's a recognised manufacturing defect. Search the forum for ST9400

 

[HootingOwl]

So it does not recognise the demand for hot water. Are you certain that it does not try to fire up, however briefly, when running the hot tap with ECO switched off?

 

[HootingOwl]

Is this a combi or a conventional?

 

[Optimusfb]

Sorry If I come across really stupid. But I have no idea about boilers. But how do you turn the backlight off on the Honeywell? Bare in mind Muggles, when I use the programmer to turn on the heating I do see the green light (the burner) appear..................so not too sure if it is the programmer?....

 

[Optimusfb]

Hootimgowl, it is a combi boiler. We do have a mega flow boiler in the loft.

I'm not too sure if the green light (burner) appears for the duration you have he hot water or heating on....

 

[muggles]

Is this a combi or a conventional?

Good shout, I'd assumed conventional but I now see its a combi, although it's feasible that it's connected to a cylinder

@Optimusfb do you have a hot water cylinder?

 

[muggles]

Sorry If I come across really stupid. But I have no idea about boilers. But how do you turn the backlight off on the Honeywell? Bare in mind Muggles, when I use the programmer to turn on the heating I do see the green light (the burner) appear..................so not too sure if it is the programmer?....

OK, ignore the heating, it's the hot water that isn't working if I've understood you correctly? ST9400C User Guide Page 13 to get into installer mode, then Page 12 to turn off the backlight

Could also be an issue with your Megaflo but you need to be G3 Registered to work on that, and I think the programmer is the most likely culprit

 

[Optimusfb]

@muggles I don't know what a hot water cylinder is? Or where would u find it....apologies if I'm not a fountain of information, it's because I don't know a lot about it. I do have boiler cover with British Gas, but apparently it started working and he couldn't fathom why?

 

[muggles]

Your Megaflo is a hot water cylinder

Bin the British Gas cover - you're better off putting the money to one side in your own account for when a fault occurs, and employing a local independent as and when needed. You'll find that over the years you've saved enough money to replace the boiler when the time comes - boiler insurance policies are only there to benefit the insurer, and yours have already demonstrated a lack of knowledge on this very common issue. Try the backlight suggestion and report back - now that we know this is an intermittent fault I'm even more confident that the programmer is the cause

 

[Optimusfb]

@muggles Thank you for the kind information and apologies for the lack of clarity on my part in providing details what the problem is. It was extremely chaotic and stressful due the lack of hot water, especially when you have a newborn in the household!


I think we are on the same page and somehow you have managed to decipher my complex messages, but just for clarity and completeness the following has been noted/experienced:


1) I have noted that the Burner light (green light) does not appear when I use the Honeywell to select hot water. You may have rightly pointed out that the two are not communicating with each other.


2) I noted that if I select hot water and in the absence of the burner light, if I put on the Eco mode I do get moderate warm water.


3) When I select to put the heating on, the Burner light appears magically.


Since I have done a loft conversion, I was strongly recommended to have a mega flow installed due to 4/5 people inhabiting the household and the water pressure would be maintained. Since the implementation of the mega flow boiler, this has become the control centre to adjust the water temperature by the temperature gauge on the Mega flow. This has never been adjusted as we have always been happy by the temp of the water.


Anyways, the irritating part is setting the Honeywell on timer so we maintain a constant flow of hot water. Judging by our habits, we normally put hot water on for one hour in the morning and in the evening and we very rarely run out of hot water. But sometimes we do not put the timer on in the evening. The annoying part is when we do run out of hot water whilst having a shower (arghhhhhhhhhhhhhhhhhhhhhhhhhhhh) From my understanding, does the water in the mega flow tank needs to be constantly heated as once that is consumed, then a fresh batch of water fills up the tank which needs to be warmed……(or am I totally wrong and I should assume if the original batch of water isn’t consumed, over time it will cool down and will need to be reheated?) I would phone the engineer who installed it, but for some reason his attitude stinks and he would find some method to charge me even if its for advice! This was the reason why I decided to sign up to British Gas Boiler cover.


Back to the original issue, once I return home from work, I will try the backlight suggestion as you have very kindly pointed out to me. If this solves the problem, going forward do you think I should replace the Honeywell? Funnily enough at that time the installer did say this was THE BEST programmer out there!! The boiler was installed in 2009, where the Honeywell and the Mega flow was installed in 2014. Im not too sure what the warranty is for the Honeywell…..


I will report back this evening with my findings….Thank you once again for your time and effort (you too @HootingOwl)

 

[muggles]

It is possible to program the timer to come on for an hour morning and evening so you don't have to remember to do it yourself. Your understanding of the Megaflo is broadly correct - the way it works is that cold water flowing into the bottom pushes the hot water out of the top when you open a tap or have a shower. After a period of time, no hot water will remain and so the cylinder needs to be reheated. If you don't use any hot water and don't reheat it, it will cool over time as it's not 100% thermally efficient.

The Honeywell is a very good timer, they just had a faulty batch. Warranty is the statutory two years unless otherwise stated, as with all products you buy in the UK. Honeywell have been known to honour the warranty for the faulty batch outside this period though, and I'd recommend replacing it with another ST9400c if it is the problem.