How to remove stubborn immersion heater blanking plug?

[frank rabbets]

With the cold tank supply turned off the hot tank will drain itself by syphon action.

Rob I had a similar sequence of events in this house when we moved in. A steel water main disappearing into extension concrete foundations with no house stop cock apart from in the lane which took days to find. The hot tank was downstairs so no hot water upstairs. Also no insulation anywhere to stop pipes freezing or heat escaping. No cover on the plastic wafer thin cold water tank which was about to burst. Cold water tank had bird skeletons in the bottom and the cold taps were directly off this so we were drinking dilute dead birds.

I decided to remove the whole water system, electric central heating and install a new water main from the lane with a meter there and install a combi boiler and central heating. All quite easy once you have plans worked out. I was surprised how simple the building regs are. I think only 3/4 basic rules. It's just like running an electric circuit with flow and return being + and - . I guessed the rad sizes and used 22mm flow and return with 15 mm for the rad spurs. I used copper above floor level and plastic "fastfit" for below floor level where it did not have to look so neat and I could bend round corners to save on right angle joints. Also the fastfit system joins copper to plasic. If you decide to go that way, especially under floor, I'll post a couple of tips which would have saved me hours. Also I even installed the boiler but had to have a qualified person to light it!! The Worcester Bosch boilers come with a manifold on the wall so when you change the boiler you just unplug and plug a new boiler in.

 

[Tractionman]

Bloody hell Frank, that was grim, dead birds in tank. are you sure this was your drinking water supply - that`s normally direct off rising mains so you have fresh water every time cold taps turned on. the storage tank in loft is just that, a storage tank, for refilling hot water cylinder etc. depending on old or new, you get all manner of sh/t in there, rust, grit, scale etc and you don`t want to be drinking any of that, yet alone dilute dead birds!! YUK!!
John

 

[silvercruiser]

Bloody hell Frank, that was grim, dead birds in tank. are you sure this was your drinking water supply - that`s normally direct off rising mains so you have fresh water every time cold taps turned on. the storage tank in loft is just that, a storage tank, for refilling hot water cylinder etc. depending on old or new, you get all manner of sh/t in there, rust, grit, scale etc and you don`t want to be drinking any of that, yet alone dilute dead birds!! YUK!!
John

Thats quite common in older places, the only tap that was off the main is usually the kitchen sink, then all the bathrooms etc came off the CWS tank. thank god its a bit better on new installs. i changed a CSW tank above a shop in lewisham that pigeons had got into and that was awful.

 

[frank rabbets]

That's how this place was built and modified over the years. Built in 1934 and the electric and water supply was laid across the surface of a sandy field at the back! I dug up the original earth the other day consisting of a square galvanised steel plate about 10 inches across with a wire tied through it. It was 2 ft down under the front patio which we had to dig up and relay because it was laid on rubbish. The water tap for the kitchen came off the cold tank which should have had a lid. That was the regulation years ago to give you 24 hours drinking water in case of mains failure. We were lucky because relatively recently they put gas, water and drainage in the lane although there are only 7 houses. I trained as a property surveyor but didn't do a survey! I found out soon after we bought that the earth and rubble from the open plan improvement had been put under the floorboards and whilst the floors were up they had plastered over the air bricks. No dry rot fortunately.

 

[Bat21]

With the cold tank supply turned off the hot tank will drain itself by syphon action.

Sorry Frank, but unless the laws of physics have been rewritten, that isn't going to happen.

 

[silvercruiser]

Sorry Frank, but unless the laws of physics have been rewritten, that isn't going to happen.

yes im afraid the tank will most definitely be full.

 

[Rob]

So today with the help of a forum member we managed to get the plug off. Found the drain valve on the back of the cylinder and found it was unsurprisingly seized. Went into the loft to figure out the piping and the pipe coming out of the top was the hot water outlet as Paul said. Opening the tap in the bath emptied the tank in the loft leaving a small about of water in the pipe above the cylinder to the T piece that leads to the hot water in the taps. As the other end of the T piece is an expansions pipe that goes to the tank in to roof there is no way the water could syphon itself out. This means I have always been working with the cylinder full of water. With no other way of getting the water out we proceeded with a few methods have have been mentioned.

Firstly tried to hit stillsons of various sizes with a lump hammer but all we proceeded to do is mangle the top of the cylinder even more. Then we tried the torch but all the heat was absorbed by the water. Even tried a cold chisel. Then I got the hacksaw out then cut as much of the seal out and finally it started to move. As we knew there will be water gushing out we decided to turn off the electricity and put an old pillow under the cylinder I found round the back of the cylinder to absorb as much water as possible. Must of spilled half a bucked of water till it stopped. The joy was short lived as when I put the immersion heater in it would not fit as it was hitting something inside. So I put the plug back on and used my hide hammer to reposition the flange and now the immersion heater fits right in.

Frank, yes I will be redoing all the plumbing and probably doing it in a similar way to you. Plastic when out of sight with copper on the visible bits. So far I have found this site is very good for domestic wiring: http://wiki.diyfaq.org.uk/index.php?title=Main_Page Have not explored the plumbing bits yet but any tips would be appreciated.

 

[silvercruiser]

Well done Rob at least you can now heat the water with the immersion. you would of been hitting the coil inside the cylinder that the back boiler primary circuit flows through to heat the water. Enjoy a hot bath now

 

[Chris]

Now that's what I call deja vu.

Still got the T shirt.

Well done Rob. So you in this new place then or do you have the luxury of getting it prepped first?

 

[frank rabbets]

I don't understand why the hot water taps if opened won't drain the hot tank with no cold tank pressure. They are below the hot tank and as the hot tank is vented to atmosphere by the expansion pipe they should syphon the tank dry. Same is true for syphoning petrol out of a car, that works?

 

[Chris]

Don't think the hot tank is vented to atmos, Frank. You gat a vacuum lock essentially. Couple of dribbles and then nothing as the negative pressure in the cylinder hold the water back. The coil is vented to atmos, but not the tank.

 

[Bat21]

Frank, it is the 'weight' of the cold water in the tank above the hot water tank that forces the hot water out of the taps. Cut off that weight and there is nothing to force the water out of the taps.

Regarding your syphoning petrol analogy, think about it.... when syphoning a fuel tank you put the tube down into the tank, to the bottom if possible. You wouldn't get much petrol out if you put the tube right next to the filler cap

 

[Bat21]

Don't think the hot tank is vented to atmos....

The hot water tank is vented Chris

 

[frank rabbets]

Just logged on to post my mistake! The hot water tap supply pipes don't go to the bottom of the tank so they won't syphon.

Yes the calorifier is vented but I was assuming an earlier type direct system where there is no calorifier and the tank must have an expansion pipe turned over the cold tank.

 

[Rob]

Well my cylinder is vented to atmosphere, followed the pipes to the loft. Don't know much about this plumbing stuff so can't tell you if this is normal but need to learn it quickly.

Got a couple of weekends or so to move in Chris. Still need to find a couple of essential white goods on ebay, then clean the place up before we can live in it. Might need to setup a temporary kitchen in the living room somehow whilst we get the extension rebuilt.

 

[Chris]

Cheers Paul, gotcha.

Good not to have to live in a building site Rob.

 

[Rob]

It will be worth living on a building site Chris, well at least that's what we keep telling ourselves.

 

[frank rabbets]

Back to school for me then. I was drawing out a diagram on a piece of paper between a petrol tank/rubber pipe and a cylinder/hot pipe when I realised my mistake.

Rob if you decide to use fastfit I'll post some tips the shop told me and also a few I learned the hard way.

 

[Tractionman]

Glad you are sorted Rob.
John