Clearing blockage in cold water feed for Boilermate 111

Last week had to have system pump replaced by Gledhill Response and the water store had to be drained down to move a pipe to facilitate access to shut off valves. Advised that the cold water feed pipe appeared blocked by sludge so water store had to be filled via the expansion pipe (backfilled??). All is working well however we are adding a radiator in an extension in a couple of months and the system will have to be drained down again to enable fitting the radiator. I am concerned that we will be unable to fill the water store in the normal way due to the blockage and again have to use the vent pipe. Questions: is there any way to unblock the blockage in the feed pipe which is internal? Also in using the vent pipe how can one tell the water store is full to required capacity?

I was advised that due to the blockage it may be necessary to replace the whole Boilermate 111 which seems a bit excessive for a simple blockage when nothing else is wrong.

Grateful your advice. Many thanks - Ian

the filling pipe on the BM3 is only a almost strait peace of 15mm pipe of max 30cm lengths, from your bolted on top tank to your inner cylinder, you could use a old metal coat hanger to pock in to the pipe to unblock and when filling , stick the hosepipe direct in to the 15 mm filling, this will force the blockade out . when the water comes out of the 22mm vent pipe, your BM3 is fully filled.( your Gledhill Response chap should know this, may he was only interested , selling a new one and making you worry)
hope this helps
regards Mario at Mario's Boiler Service

Many thanks for that Mario, very helpful. There is a bend where the filler pipe exits the header tank and goes down into the water store. I was told it was a long pipe with a bend at the bottom which does get clogged up with sludge which is certainly different from what you advise. My own plumber/heating engineer made the same suggestion as you regarding putting a hosepipe over the inlet and blasting the blockage out with normal mains pressure whcih would make sense for the short pipe you advise. Any problem with possibly too much mains pressure in doing this? I also have a thin flexible unblocking wire which I can try.

Many thanks again.

Mario,

Have to advise I have discovered that my BM3 has a long pipe from the F&E tank to the bottom of
the water store and then u-bends up a short distance into the store. I have tried to unblock it using my flexible wire and got out some gunge but not all yet. Will probably try the hosepipe method at some stage.

Ian

Ian Cox wrote:Mario,

Have to advise I have discovered that my BM3 has a long pipe from the F&E tank to the bottom of
the water store and then u-bends up a short distance into the store. I have tried to unblock it using my flexible wire and got out some gunge but not all yet. Will probably try the hosepipe method at some stage.

Ian

This is how they usually are arranged. There is little chance of clearing the blockage as it is lime scale, a solid stone-like material. (There is an arcane technical reason why it will be limescale and not the softer and more common ferrous oxide deposit usually found in a heating system.)

The quickest and most successful fix is to abandon the existing cold fill arrangement and to fit a new pipe. Drain the system, unscrew the drain cock at the bottom, connect a pipe into it and run this pipe vertically up to the header tank. Drill through the side of the header tank and fit a tank connector. Connect the new copper pipe into it and refill the system via the new pipe.

Hope that helps,
Mike

Thanks for your advice Mike, a relatively easy fix! However you mention it will be limescale and not the ferrous oxide. I have always used the correct inhibitor in the system and the cold water supply is softened water; would this still produce limescale?

Thanks

Ian

Ian Cox wrote:Thanks for your advice Mike, a relatively easy fix! However you mention it will be limescale and not the ferrous oxide. I have always used the correct inhibitor in the system and the cold water supply is softened water; would this still produce limescale?

Thanks

Ian

Ian,

You're welcome. If your softener has been working correctly all along, the no it can't possibly be limescale as the softener removes virtually all of the dissolved calcium from the water.

On the other hand, if you have a solid blockage you cannot shift mechanically, this suggests the softener is not working correctly....

Mike