Leak or broken boiler

[Jagjourdan]

Hi Guys,

I have had a search of the forum to see if I can find a thread related to my issue with no luck so have created a new thread. I bought a house back in March this year that has a Worcester Bosch greenstar 25Si boiler. I’m going to go into a lot of details as I think explaining the whole process will paint a clearer picture into hopefully identifying the problem.

House has been completely renovated, some of the pipework changed but the boiler stayed. This was due to the hot water/radiators working when we viewed the property so didn’t see a point to spend extra money which seemed unnecessary. At times when certain work was done I.e removing the old ceiling the boiler was not covered and I’m assuming lots of dust/debris has fallen inside the boiler. This could have caused damage.

We have had a plumber who has done the majority of our plumbing work, he has been difficult at times to get hold of, says he coming then doesn’t show up. He’s been rubbish ultimately and we have had to get other plumbers in to fix some of his work and ultimately finish the job as he went awol. He was working on a day rate so fortunately he hasn’t ran off having been paid.

One thing he did however do during his last visit was pressurised the system, the hot water wasn’t on as we needed our electrician to come and actually connect the boiler for power however the system was live and any leaks would have been seen from the system going live.

The electrician has since connected the power to the boiler and we have had had to get another plumber in to service the boiler, and install some radiators too whilst also connecting the gas hob to the mains. This was done a week ago. He tested the radiators and the hot water and we were happy with the work undertaken. A gas certificate was supplied.

We have however since had issues, we don’t currently live at the property as it is unfurnished, we do stop by daily. During our visit the next day we noticed a strong gas smell coming from the kitchen, we called cadent, they identified that this plumber had not tightened a nut for the connection from the gas mains to the hob. Unbelievable !!

Gas Mains was turned off immediately and plumber came next day to rectify.

After him connecting the gas mains to the hob properly after he left I tried to turn the central heating on. We have a google nest 3rd generation, turning the heating on via manual mode or via the thermostat itself done nothing, boiler did not signal that it had received a signal to turn the heating on.

Got the electrician to come back and check everything, he checked and showed me the issue wasn’t with the thermostat. Now here is the issue as to why I am writing this post. Had another look at the boiler and I had seen a lot of condensation coming from the dcw mains in pipe and the dwc in connection to isolating valve.

I was able to identify the pipe names by viewing the manual for my boiler here.

https://www.freeboilermanuals.com/assets/pdf/worcester_bosh/Greenstar-25-30Si-Compact-ErP.pdf

The pipe in question is shown on page number 8 as item 44.

There is so much condensation that it’s dripping causes a small puddle below the boiler and onto the worktop. I have attached a picture to this post. It doesn’t showcase the issue in great detail but hopefully helps paint a picture.

As a result called the plumber back again, he reassured me that it’s just condensation and is normal, given him messing up the gas hob connection I’m now skeptical of what he says. He states that the condensation is normal and nothing to worry about. Looking outside I can also see water marks on the floor as a result of water leaking from the condensate pipe.

I ask him how comes the central heating is not turning on. He has a look at the boiler and states that the boiler is calling for hot water even though the taps are off (pic attached) and as a combi boiler prioritises hot water it never turns on the central heating as it thinks there is a continual demand for hot water. The hot water sign on the boiler is continually on. As the boiler thinks the hot water is required the boiler is on and makes an idle noise, it does however only get louder and steam come out the flute in large quantities when the hot water is actually turned on. He goes onto say that there’s either a problem with the boiler or a leak. He apparently proves this by turning off the dcw mains isolating valve which stops the boiler from thinking hot water is being called and subsequently the central heating turns on. I’m now stressing as we’ve just had flooring put down, bathroom tiled and kitchen units installed which if a leak is present ( which we don’t know where) would have to come up and be very expensive. I had assumed that the system being live before would have shown any potentially leaks. There was a few leaks actually identified at this point and rectified, is it possible that a leak could not show when a system is live but only cold water flowing through but then leak when hot water is flowing through the same pipe?

Also if this had been an existing issue he would have identified this when he came and serviced the boiler as the radiator would have not turned on at all back then as the boiler would have still assumed hot water was running.

I’m hoping this is a boiler issue and not a leak, I’m hoping the excessive condensation perhaps helps point toward this being a boiler issue. I know it isn’t a new boiler and may have gone through a bit of a battering during our renovation work. Is there any checks/ things I can do to help identify that this is most likely a boiler issue?

PS: I did have another 3rd plumber come today and he said whilst it may be condensation he’s never seen condensation like that. He just came to have a look so did not do anything to help him identify what the actual issue is so couldn’t really say.

I know this is a long read- any help would be greatly appreciated

 

[flameport]

Most likely it's a boiler problem(s).

Sack the 'plumber' that left a major gas leak - there is absolutely NO way that should have happened. Even if they were incompetent enough to leave the connection loose they are supposed to do a tightness test before leaving the installation.

 

[Jagjourdan]

Hi there, thanks for your reply.

Can I ask what makes you think it’s most likely a boiler problem. Are there specific symptoms based on my original post that points toward that?

 

[dilalio]

Get your gas safe engineers / plumbers from somewhere other than chance-a-trader or TryBuilder.com it's a lottery who'll you'll get through the door.

Boiler needs checking over, sorting and then monitoring for further issues with system.

If I were you, turn off main stop cock to property whilst you're not there!

Edit: also ask to see their gas safe ID card and take the number... Tell them you've had a bad experience and aren't taking any more risks.

 

[dilalio]

they are supposed to do a tightness test before leaving the installation.

And local testing with LDF.

 

[Jagjourdan]

Thanks for your replies. Based on your responses so far I’m assuming you’re inclined to think that it may be a boiler issue? I’ve also noticed when I do turn off the cold water mains valve and turn the central heating on that the pressure creeps up from 1.5 to 3 bar. I’m assuming this is not normal?

 

[flameport]

the central heating on that the pressure creeps up from 1.5 to 3 bar. I’m assuming this is not normal?

Pressure will increase when hot because the water in the system expands. 3 bar is rather high, likely the pressure vessel needs to be recharged. However that is unrelated to the not working problem.

This is definitely wrong:

The hot water sign on the boiler is continually on.

turning off the dcw mains isolating valve which stops the boiler from thinking hot water is being called and subsequently the central heating turns on

With the mains water on, is water actually flowing? If there is a water meter, look and see if the numbers/disc are moving when the boiler water supply is on, and if it stops when off.
If water is flowing (even very slowly) this could be a tap or other outlet passing, or a leak on the hot water system. Check everything including cold outlets, as it's certainly possible that things could have been connected wrongly, including toilets connected to the hot supply in error.

It won't be a leak on the heating side.

 

[Stuckinarut]

When you say the hot water sign is continually on, do you mean the preheat as shown in your photo? If yes, then boiler stuck in preheat and likely heating the radiators up.

Turn the preheat off and then report back if the heating no water works as it should and the hot water symbol has gone off.

they are supposed to do a tightness test before leaving the installation.

Not strictly true if they have isolated locally, only have to test for a leak using a form of leak detection as per @dilalio.

pressure creeps up from 1.5 to 3 bar. I’m assuming this is not normal?

No not normal, you have an expansion issue, likely the vessel as per @flameport.

@Jagjourdan - the 3rd photo, is this showing “condensation”?

 

[Jagjourdan]

Pressure will increase when hot because the water in the system expands. 3 bar is rather high, likely the pressure vessel needs to be recharged. However that is unrelated to the not working problem.

This is definitely wrong:



With the mains water on, is water actually flowing? If there is a water meter, look and see if the numbers/disc are moving when the boiler water supply is on, and if it stops when off.
If water is flowing (even very slowly) this could be a tap or other outlet passing, or a leak on the hot water system. Check everything including cold outlets, as it's certainly possible that things could have been connected wrongly, including toilets connected to the hot supply in error.

It won't be a leak on the heating side.

Unfortunately there is no water meter otherwise this would make the issue a lot easier to identify. We just pay a fixed price regardless of how much water is used.

All taps turn on correctly I.e hot turns on hot and cold turns on cold. Toilet is also cold from the mains.

There was about a 2 month period whereby we only had cold water supplied to the house whilst waiting for the old plumber/ electrician to come.

Surely any leaks in the system would have been exposed during this period?

 

[Jagjourdan]

When you say the hot water sign isn’t continually on, do you mean the preheat as shown in your photo? If yes, then boiler stuck in preheat and likely heating the radiators up.

Turn the preheat off and then report back if the heating no water works as it should and the hot water symbol has gone off.

Not strictly true if they have isolated locally, only have to test for a leak using a form of leak detection as per @dilalio.

No not normal, you have an expansion issue, likely the vessel as per @flameport.

@Jagjourdan - the 3rd photo, is this showing “condensation”?

Hi there, the issue is the hot water sign is on continually.

Yes, 3rd photo shows condensation

 

[Stuckinarut]

Hi there, the issue is the hot water sign is on continually.

Did you read my post? I edited as for some reason autocorrect on iPad changes the word is, to isn’t.
Anyway, Turn the preheat off and update please

Yes, 3rd photo shows condensation

That’s not condensation, that’s a small leak.

 

[dilalio]

If preheat (DHW) is Off but the tap symbol still remains on the display then the boiler is detecting a "demand" for hot water and is trying to fire up to serve this.

The demand call could be due to a leak from the flow turbine or adaptor within the boiler. It is very common for these to fail and leak and is why Worcester retro-designed a bright green, rubber umbrella to protect the diverter motor.

If the leak is after the turbine (downstream) then this is likely causing the demand. It would seem the likely cause of the leak you are seeing below the boiler but it needs a repair engineer to confirm and remedy.

If the issue persists, once that has been confirmed and rectified, then there is a leak on the hot pipework elsewhere or as @flameport a toilet has been connected to the hot pipes which is more common than you may think.

Edit: if you haven't already... Isolate cold inlet on boiler and check all hot outlets are off and that wc cisterns all refill.

 

[dilalio]

Surely any leaks in the system would have been exposed during this period?

Other trades can screw through pipe which hold at first then begin to fail.

If the house has been left unheated has there been zero temps in your area leading to pipes freezing?

Get the boiler sorted first. Clean and dry it all up underneath (with power off) and see if it immediately starts to drip.
Condensation blossoms everywhere at the same time. If you look closely with a torch you can see the water droplets forming on several surfaces at once.

I'm not there but not convinced about the condensation theory!

 

[Jagjourdan]

Hi guys, thought I would close with an update. It was ufortunately as you all had assumed but I didn’t want to believe… a leak.

Luckily I had a rough idea of where it could be if it was leaking and I was right. Dodgy elbow used by the plumber. Leak resolved and boiler now operates as intended.