Search the forum,

Discuss Glow Worm Fuelsaver 40B Mk2 Heat Exchanger Kettling in the USA area at PlumbersForums.net

Messages
21
I have an old Glow Worm Fuelsaver 40B Mk 2 installed on the kitchen wall.
In November, the heat exchanger began making a kettling noise.



It’s done this before. In the past, simply draining and refilling the system to flush out loose deposits was enough to stop the noise.
In November 2021, I tried using Sentinel X400 cleaner which I left in for a couple of weeks. I flushed the system and added Fernox MB-1 and 500ml of Sentinel X200 noise reducer.
This seemed to help for a while but the kettling noise is now back.

I have a bottle of Fernox F3 but when I tried that in the past it made little difference.

I considered trying an acid based cleaner such as DS-40 but am a bit worried about it causing leaks in the radiator valves.

Directly above the boiler is a drain cock used to empty water in the pipe that runs between the boiler and the airing cupboard upstairs. The heat exchanger also has a drain plug at the lowest point. I wondered whether it would be feasible to drain the heat exchanger via the plug and use the drain cock above to fill it with acid cleaner (using a short hose and a funnel). I could leave the acid in place for a day or two (the heat exchanger is made of copper) and then drain and flush it via the plug.
That way the acid cleaner would not enter the radiators or the rest of the heating system.
One concern would be whether the drain plug would actually unscrew after not being touched since the boiler was first installed years go. If attempting to remove it damages the heat exchanger then it would be game over. Does anyone have experience removing the heat exchanger drain plug? Does it need a new (copper?) washer when re-fitting? If I have to get a new boiler, I would rather wait for warmer weather.

An alternative might be to try just draining the system again and adding more X200 as a stop gap measure.

Any suggestions?
 
The pump is working / not 15 years old / failing ?
 
The pump is working / not 15 years old / failing ?
I don't think there is a problem with the pump.
It's set to the lowest speed (1). I have tried running it at faster speeds (2 & 3) to see if it would help clear loose debris from the heat exchanger.

I have a pipe thermometer on the boiler outlet. The boiler stat is set about half way (2.5).
That corresponds to a water temp of just over 60degC measured at the outlet pipe.
The kettling noise only happens as the water temp reaches above 50degC.
 
Update:

I put up with the kettling noise for a while but last week decided try the Fernox F3.
I wasn't convinced it would help if the problem was limescale in the heat exchanger.

I left in it for a week and ran the heating morning and evening as usual.
Yesterday I drained and flushed the system and added MB-1 inhibitor + Sentinel X200 noise reducer.
The water that came out looked pretty clean - just a slight brown colouration from the F3.
For the last 2 days, the boiler seems to be back to normal and has been running quietly. Fingers crossed.
 

Reply to Glow Worm Fuelsaver 40B Mk2 Heat Exchanger Kettling in the USA area at PlumbersForums.net

Similar plumbing topics

  • Question
Ideal Logic 24, Previous problem was that the hot water was only cold or barely warm if the heating was in use. If heating was off and boiler cold then would get hot water most of the time. Changing the flow cartridge about 2 years ago (when I moved in) solved this problem enough to suffer it as...
Replies
1
Views
75
We run a community village hall and have a large kitchen provided for the use of hirers. This includes a Lincat SLR9 gas cooker which I believe is a 23.8Kw appliance with all six burners and oven on max. This was installed some 10 years ago and has passed all subsequent Gas Safety inspections as...
Replies
4
Views
365
Hello all, I’m replacing a concrete paving slab patio in the back yard. The original patio used 50mm deep concrete slabs on hardcore & sand. I’m planning to pour a 100mm deep concrete patio on 100mm hardcore. In order to achieve the same final height to line up with the rest of the patio, I...
Replies
6
Views
212
Hi all. Hope you have all been keeping well. A while back I decided I only wanted to fit one brand of boiler and decided on Viessmann due to space for servicing and changing parts if ever needing to. I am finding my decision rather hard due to the different clearances on flue runs and cupboards...
Replies
9
Views
133
We are from Alberta, and I own an electrical company. I have been asked by a BC Mechanical P. Eng. to install an emergency STOP button at the man-door to the boiler room. It's intent is to 'halt' the operation of the boilers in the room should there be an emergency. He is demanding that I do...
Replies
5
Views
227
Creating content since 2001. Untold Media.

Newest Plumbing Threads

Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock