Bubbling Boiler and Clanging Pipes!

[roverblue]

Hi there,

I have recently been having an issue with the actuator on my boiler, still havent got around to replacing it as yet so manually turned the valve on HEATING as a temporary measure.

//www.diynot.com/forums/plumbi...itching-manually-setting-help.345072/#2581390

I know have a new issue, when the boiler kicks in the pipes start clanging and i get too scared to ride it out and turn it off!

If i then bleed the nipple valve in my airing cupboard lots of air comes out then finally water. I can then restart the boiler and after a bit of groaning it will come on.

My problem is that its getting worse, I now need to repeat this process about 6 times before the boiler will come on and it seems my downstairs rads arent very hot anymore.

I also hear bubbling noises when the boiler kicks in as if the pipes are full of air. I cant work out though how this air is getting into my system?

I can bleed the rads and a little air comes out before water, like i say the nipple near the pump in the airing cupboard is constantly filling with air.

I have checked the feeder tank in the attic and it is full, could it be blocked somehow?

Thanks,
Roverblue

 

[45yearsagasman]

A restricted cold feed connection can cause air to be sucked down the open vent on start up and during operation. If you have the skills then it is diyable.
This diagram may help to understand the connections to your system. View media item 39013

 

[roverblue]

thanks Pete, its freezing here so hoping to get it sorted today. I have been up in the loft and looked at my FE tank, the pipework looks a little different to how you have displayed it though.. the cold feed from my FE tank seems to attach to the vent in the loft and the the vent pipe then comes down into airing cupboard and is attached just below the pump as you show.

is this dodgy or standard practice?

thanks in advance for your help, much appreciated as always on here

 

[ianmcd]

if you have a magnet of any description see if it sticks to the copper pipe from the FE tank where it connects to the system, if it does stick that is where your blockage is

 

[roverblue]

ok tried the magnet but doesnt appear to be sticking anywhere along that run. I noticed the vent pipe was fairly warm and the water in the FE tank also slightly warm is this normal?

One thing i did notice is that the pump was very hot, and the problem seemed to start when the boiler first kicks in. It makes a whooshing noise and the bubbling came after.

So next question is the pump potentially on its way out? I have upped it to the top speed and so far so good, turned on boiler and no whooshing or bubbling noises.

If the pump cant circulate the water quick enough would the boiler get unhappy and start clanging about?

 

[JohnD]

If the pump is very hot then water is not flowing through it correctly. It might be jammed with sediment, or blocked, or full of air. Open the silver screw in the middle, see if air comes out, see if you can turn the end of the spindle with a screwriver in the slot. When you bleed the highest radiator in the house, does water squirt out forcefully?

Have you given the system a chemical clean yet?

Go and watch the F&E pipe while someone turns the heating on and off. You might find water is pumped over through the vent pipe when the pump starts. This will introduce air to the water and cause corrosion.

Sometimes a chemical clean will remove a partial blockage which is interfering with correct flow. It is a very easy and cheap job so worth a try.

Turning down the pump speed may help while you deal with it.

Tie up the ball float and bale out the mud from the F&E before you add the cleaning chemical, and drain a bucket of water from the drain cock so the chemical is drawn down when refiling.

Adjust the ball valve in the F&E so there is two inches of water above the ports in the bottom where the F&E pipe is.

 

[roverblue]

ok, bled the pump and no air came out just water dribbling from the bottom. When i bleed the radiators water does come out, i wouldnt say forefully though as in it shoots clear of the metal?

next to try the FE tank to see if water is being drawn in, if not guess it is blocked pipe work?

not sure on the pump, its as old as the house (1991) by the looks as it has decorators paint splatter. It really is hot to the touch when in operation which doesnt sound good.

will let you know how i get on...thanks again for the help

 

[roverblue]

hi all,

just an update on this, after leaving the pump on max setting for an hour and then turning it down the bubbling has ceased. I guess air was trapped somewhere in the system and by speeding up the pump it has pushed it along.

As my actuator has been on the blink for the last couple of weeks I dont know if its related to this. I have been manually turning the spindle to point at heating, and taken the SUNVIC actuator off. I thought i had positioned it towards the HEATING side but now I am not sure as it rotates 360 degrees.

Does anyone know which way the flat side would be facing if the motor was pointing it at heating?

Thanks,
Roverblue

 

[roverblue]

been running the last few days with no problems, with the pump at top speed it seems to have stopped the bubbling and clanging noises.

Could this have been due to the boiler "boiling" the water due to the pump not sending the water away from the boiler quick enough? Is this a sign of a new pump being required?

Cheers,
RoverBlue

 

[JohnD]

Have you given the system a chemical clean yet?

 

[roverblue]

Hi John, no not given a clean moved in 6 months ago but based on state of place doubt it's had one for a while. Would this be responsible for needing to turn the pump up? Thanks for your help and advice

 

[JohnD]

A chemical clean will do nothing but good. Most likely you have sediment sludging up the pipes and bottoms of radiators, given time it can form a serious blockage.

If the pump is very hot then water is not flowing through it correctly. It might be jammed with sediment, or blocked, or full of air. Open the silver screw in the middle, see if air comes out, see if you can turn the end of the spindle with a screwriver in the slot. When you bleed the highest radiator in the house, does water squirt out forcefully?

Have you given the system a chemical clean yet?

Go and watch the F&E pipe while someone turns the heating on and off. You might find water is pumped over through the vent pipe when the pump starts. This will introduce air to the water and cause corrosion.

Sometimes a chemical clean will remove a partial blockage which is interfering with correct flow. It is a very easy and cheap job so worth a try.

Turning down the pump speed may help while you deal with it.

Tie up the ball float and bale out the mud from the F&E before you add the cleaning chemical, and drain a bucket of water from the drain cock so the chemical is drawn down when refiling.

Adjust the ball valve in the F&E so there is two inches of water above the ports in the bottom where the F&E pipe is.

 

[roverblue]

Hi John,

I definitely have a sludge problem as since i turned the pump up 2 radiators no longer get hot (1 upstairs and 1 down). Plan is as follows...

- Buy 2 Sentinel X400
- Take off 2 problem rads and hose outside to clear blockages
- Drain all system
- Refill system with water and drain again
- Repeat refill/drain until water is clear
- Put back 2 radiators
- Add Sentinel X400 to Expansion tank
- Refill system
- Leave it running till mid/late Jan
- Drain system till clear (repeat as necessary)
- Replace existing pump and 3 port valve (having problems with both of these)
- Add 2 Sentinel X100 to feeder tank and refill system.
- Walk around hot house in my boxers with a cool beer.

Should cost about £150 and a lot of my time, the alternative is to just replace entire system for a new combi boiler but will cost over £2k which I don't have.

Does this sound a good approach, I am reasonable at DIY and my brother is an electrician so can do the wiring bits?

Do you think its worth fitting a Magnclean to the system whilst I am at it for the extra £100?

Hopefully that will mean the house has a good maintenance overhaul and I can get on with renovating the rest of the house in warmth!

Thanks,
RoverBlue

 

[JohnD]

sounds fine to me

if you can afford an extra £100 and can do basic plumbing, add a system filter on the Return pipe to the boiler, the sooner the better. It will trap circulating particles and prevent them building up into new blockages.

The plastic Magnaclean is spectacularly fast at collecting black sludge, but they tend to leak, so I would go for a brass one such as the Spiro or Sentinel versions, which have a vortex trap.

btw fitting the new pump earlier will perhaps improve flow while the cleaning process is going on, and help the loosened sludge to move.

 

[roverblue]

Hi John,

Thanks again for all your advice, I have done a bit of searching online and will also invest in a Spirotech MB3 whilst I am tinkering with the pipework for the pump and valve replacement.

Hopefully that will extend the life of the system for a good while as I really cant afford a new boiler and heating system!

I didn't plan to replace the pump too early in case the sludge would break it whilst the X400 is doing its stuff. Would it not matter then?

Also I noticed my expansion tank has no lid and just a piece of plastic over the top, had to clean loads of gunk out. Would investing in a proper plastic lid for this be a good investment, presuming they still make the size i need?

will report back on progress....

Cheers,
RoverBlue