I HAVE A 4 YEAR OLD 30 CI PLUS WHICH HAS STARTED LEAKING FROM THE REAR LEFT HAND SIDE. I HAVE LOOKED AT IT AND IT LOOKS LIKE SOME SORT OF STORAGE TANK ON IT. DOES ANYONE KNOW HOW HARD IT IS TO CHANGE THIS AND CAN I DO IT WITHOUT TAKIN THE BOILER OFF THE WALL

PIGGIN HARRIS, December 2007

The original tanks are a poor design and do leak. Mine failed long ago as I was had one of the first of these boilers to be released. No assistance to pay for it from Glow worm and at the time a replacement identical part was £250. I took the boiler off the wall and by passed it completely. Been working great for 5 years or more since.
It is an electrically heated storage device that keeps hot water constantly at the ready so you get hot water faster from the tap. When the boiler has heated up the water, it switches from the accumalator to the gas heated water.

Martin, April 2014

I too had the same problem, water leaking from the rear left hand side of the boiler. Looked the problem up on the internet to see if I could buy the part direct and get a plumber out to fit. Saw some of the posts regarding it might be a defective part so phoned glow worm after sales 01773828100 and explained the problem. The young man on the phone suggested it might be the micro accumulator tank and I could book a single repair for a cost of £250.00 (for all parts and labour). I told him about the information I'd read on the internet regarding this might be a faulty part and that Glow Worm had repaired it free of charge in the past. He went away to speak to his manager who confirmed that if it was this problem, it would be fixed free of charge. I still had to pay the fee to book an engineer, he came the next day and confirmed the faulty part, made a phone call and I had a full refund on the same day of his visit. Another appointment had to be made to install the new part as it is a 2 man job as the boiler needs to be removed from the wall. The engineers arrived a couple of days later, giving me a phone call an hour before arrival. I have to say that the 2 engineers were extremely considerate and courteous, they turned up at 9 o'clock and were finished by half past 10, there wasn't a single bit of mess to clean up, if I hadn't seen them arrive, I wouldn't have known they'd been at all. Well done Glow Worm and you're engineers, you've renewed my faith in tradesmen!! I'm not sure if they carry out this repair free of charge as standard, but it's worth mentioning it when you phone in the first instance.

Dave, September 2010

no it must be taken off wall and stripped

neil, September 2010

Hi Chris.

The thing to look out for is the tall (almost full boiler height) tank in the back left corner of the boiler as you're looking at it.

The old design of Micro Accumulator Vessel tank is basically two plastic tank parts bolted together. They have replaced this with a one part stainless steel tank.

I have some photos of the old tank if anyone's interested.

I called them and booked a service out on their fixed repair fee of £250. Responded very quickly, sent one engineer out to investigate and confirm fault, and then sent a two man team out the following day to actually do the repair.

Drained the boiler, took the unit off the wall, swapped the tank, refitted, all in just over an hour.

I then rang up glowworm's support desk and stated that I was a bit unhappy about the fact that the tank had split in the middle, and if it wasn't a design fault, why would they change it to a one piece tank. Two minutes on hold and they came back with an instant refund.

Can't blame them really for trying their best to get out of it, all I'll say is a big thanks to Louise below for giving this information in the first instance. Thank goodness for the internet.

Good luck.

Rich D, August 2010

can someone confirm that i looked at a boiler yesterday and found it too is leaking ..is this because of a design error ???
if so do glow-worm replace as such for free ??
just spoke with there technical and no mention was made of this (sneaky sods )

chris plumb, August 2010

Hi folks,

I have had the same issue develop on my 30ci Plus as well. Boiler's about 7 years old but hasn't really had any serious use until the past 18 months.

Has anyone got a name or contact number at Glow-Worm that acknowledged the design fault, or any sort of written confirmation from them, e.g. an invoice or repair sheet that states "repair to micro accumulator design fault" blah blah?

I have just booked one of their engineers to come out to me, on the agreement of a £250 fixed fee for the repair, and a refund if it is an acknowledged fault. I can see they're going to try and deny it, so I'm just trying to arm myself with something!

Appreciate any help.

Rich D, August 2010

I have just had the same problem on my 30CI Plus and having rung Glowworm they have confirmed that they will replace it free of charge. It is a 2 man job as the boiler has to be removed from the wall to replace the part and should take 2 hours. Thanks to Louise for the post as I had already ordered the part which was to cost £230 plus VAT then fitting cost on top. Now it will cost nothing.

Richard F, August 2010

The leaking micro accumulator vessel on my 30ci Plus has just been replaced by Glow-Worm free of charge. Very many thanks to Louise for her earlier post, without which I wouldn't have known this service might be available!

Paul S, June 2010

I also have a Glow worm 30 CI PLUS which as of this morning has started doing the same thing as the original poster's, leaking from the left hand rear side. Having had a closer look it I can confirm it is the Micro Accumulator Vessel and NOT the expansion vessel as was suggested by another poster.
I am keen to know how other people who have suffered this problem got on with Glow worm regarding this being categorised as a "design fault"

Rapahel T., May 2010

I have only just come across your question, as I have the same problem and was looking to see if others had. My plumber tells me that he has come across this problem before, last year, and it was a leaking Micro Accumulator. Apparently Glowworm acknowledged it was a design fault and fixed it for nothing. I am currently waiting for one of their engineers now - and they have said that if it is the same part, they will reimburse the £105 I have paid upfront. So worth checking (as he tells me it could cost me c. £200 for him to fix)

Louise, January 2008

it sounds like the expansion vessle and you have to take the boiler of the wall to replace it.

peter.p., January 2008