No Hot Water, No Heating, Hot Steam coming out in the Loft!

[zjyboy]

Since yesterday evening, our hot water&heating system seems to have shut down of a sudden.
When I switch on the Gas boiler, it starts to draw water and heat it as usual, it sends the hot water to the indirect water cylinder as usual, and then it gets odd. The boiler heats again and then stops, no hot water coming to the cylinder for a long time, and up in the loft, the smaller tank - feed and expansion cistern (f&e) got hot steam blowing out, sends the whole loft steamy. And the boiler it self is very hot so it's not heating anymore, the water cylinder stays cold forever. radiators obviously not on either.
The pump seems to be fine as it pumped hot water once from the boiler but not again and again. boiler still does its job of heating the water. I am just buffed, CAN ANYONE HELP ME PLS? this has happen suddenly...

 

[JohnD]

How deep is the water in the feed and expansion tank?

When you bleed the highest radiatore in the house, does water squirt out forecfully?

Is the circulating puimp hotter than the pipes going into it?

Turn the boiler off UFN.

 

[zjyboy]

How deep is the water in the feed and expansion tank?

When you bleed the highest radiatore in the house, does water squirt out forecfully?

Is the circulating puimp hotter than the pipes going into it?

Turn the boiler off UFN.

Thanks for posting.
the f&e tank has about half-full of water.
The radiator only bleeds air, the thing is I normally closes the heating valve cos I just want hot water. and that was not achieved like normally it would.
the pump is hot when the first round of hot water come up from the boiler, but i wouldnt say its hotter that the pipes going into it. they r all very hot. the problem is that this heating & pumping process is not repeated as usual, and the steam comes out in the loft.

 

[JohnD]

keep bleeding the highest radiator and leave the bleed valve open, if necessary for ten minutes. Does the air stop coming out? Does water start coming out?

Do you know when (if) the system was last cleaned, or inhibitor added?

How old is it?

How long have you lived there?

[ I normally closes the heating valve cos I just want hot water. and that was not achieved like normally it would.

Don't understand. Please explain. What valve?

 

[joe-90]

What's your mothers maiden name? Ve haff vays of making you talk.

 

[zjyboy]

keep bleeding the highest radiator and leave the bleed valve open, if necessary for ten minutes. Does the air stop coming out? Does water start coming out?

Do you know when (if) the system was last cleaned, or inhibitor added?

How old is it?

How long have you lived there?

[ I normally closes the heating valve cos I just want hot water. and that was not achieved like normally it would.

Don't understand. Please explain. What valve?

The system is quite old, 20 years i may say. I have lived here for 2 years, no problem with the system untill now.
the valve is to switch on or off the heating, i normally leave the heating off, just have the hot water, u know.

 

[JohnD]

what does this valve look like?

what were the results of the extended bleeding?

 

[zjyboy]

what does this valve look like?

what were the results of the extended bleeding?

air bleeding stops, no water coming out. pls note i have the system switched off now cos of the steam in the loft.

the system is old, hence the valve is like a single handle, when its alligned with the pipe it's open, when its perpendicular to the pipe, its closed, normal valve. just to open/close heating.
i start to wonder whether its because of too much air in the system, that water can't b pumped??

 

[JohnD]

Almost certainly you have a blockage in the feed and expansion pipe from the tank in the loft, that is supposed to top up the water in the system.

I know this because bleeding the top radiator does not get water squirting out, but there is water in the F&E tank.

The blockage is almost certainly at the joint where the 15mm F&E pipe joins the 22mm circulating pipe. It will probably be near the pump and/or the boiler and/or the cylinder. If you hold a magnet against the copper pipe it will be attracted to the black iron oxide inside.

There is a faint chance a drowned mouse or something in the F&E tank might be blocking the outlet at the bottom, especially if there is no close-fitting lid. I expect there will be a lot of mud at the bottom of this tank. Bale it out into a bucket and sponge the tank clean with a drop of bleach until you have fixed the problem. It is now too late to use a cleaning chemical, because it will not pass down the blocked pipe. If you have a wet-and-dry workshop vac there is one thing you can try.

If you are not fond of DIY plumbing you will have to get local recommendations for someone to cut out the blocked section. It does not need a heating engineer as there is no work needed on the boiler.

 

[Gywndy]

Almost certainly you have a blockage in the feed and expansion pipe from the tank in the loft, that is supposed to top up the water in the system

Agreed - take a look at this post as well - //www.diynot.com/forums/plumbing/gravity-hot-water-system.346133/#2593295. The original post has been edited for some reason but the problem was similar to yours.