Sorry this is a long one,ding dong.I have an old CH system 2 pumps one for CH which is working fine and one for HW the pump is working fine but no HW coming from the taps there is no zone valves you can only have HW if the CH is on. sounds like an air block but I cant shift it,also the back boiler in the fireplace produces no hot water Tried draining the cistern and refilling but still nothing,Anyone please HELP going mad.Ian
No hot water
- Thread starter spooky66
- Start date
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that's pretty vague description of your system/problem.
When you say no hot water from the taps do you mean;
1) the water from the hot taps is cold
2) there is no water at all, coming from the hot taps.
what do you mean by it "sounds" like an air lock?
When you say no hot water from the taps do you mean;
1) the water from the hot taps is cold
2) there is no water at all, coming from the hot taps.
what do you mean by it "sounds" like an air lock?
do you mean you can only have CH if the HW is on? which is the usual for old gravity hot water systems?
otherwise in the summer your house would be too hot and wasting alot of gas if you had to have heating on to get water for a bath.
does the heating work? as you only say the CH pump is working fine not the heating itself?
if it is then you may have an airlock in the hw pipes. the only way i know of to get rid of the air is to locate the drain plug for the system which normally branches from the HW primaries on an old system (usually around the bottom of the boiler for example) and open it allowing any air to be forced out by the flow of water from the top up cistern in the loft. this method worked for me.....
otherwise in the summer your house would be too hot and wasting alot of gas if you had to have heating on to get water for a bath.
does the heating work? as you only say the CH pump is working fine not the heating itself?
if it is then you may have an airlock in the hw pipes. the only way i know of to get rid of the air is to locate the drain plug for the system which normally branches from the HW primaries on an old system (usually around the bottom of the boiler for example) and open it allowing any air to be forced out by the flow of water from the top up cistern in the loft. this method worked for me.....
some good systems even have a bleed valve on the HW flow pipe at the hot water cylinder end. have a look there too. you will see two pipes one above the other on the side of the cylinder. if there is a bleed valve at the cylinder end it will most likely be on one or near to those pipes.
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Hay thanks for quick reply,The heating is working fine just no hot water coming to taps, I have drained the system 6 or 7 times now but no change,had a look at cylinder I can see the two pipes one above each other but there is no valve.Thanks anyway Ian
In spite of two people asking you its still not clear if:-
Water comes out but is cold
OR
No water comes out.
We cannot advise you until you explain CLEARLY whats going on!
Tony
Sorry,water comes out from taps but is cold
If you have refilled with the F&E tank then the feed is not blocked.
That then leaves the hot water heating coil. It could be airlocked.
There should be an air bleed screw or cap or a pipe to the vent from the upper heating coil connection.
Can you post a picture of this?
It could also be a blockage in the heating coil. This most often occurs at the actual connection to the coil. perhaps you should partially drain and disconnect both connections to the coil?
Tony
That then leaves the hot water heating coil. It could be airlocked.
There should be an air bleed screw or cap or a pipe to the vent from the upper heating coil connection.
Can you post a picture of this?
It could also be a blockage in the heating coil. This most often occurs at the actual connection to the coil. perhaps you should partially drain and disconnect both connections to the coil?
Tony
Thanks again for your help,I dont see anyway other than disconecting the pip there is ne bleeding valve that I can see, loaded some images just to make shure I am on the right pipes thanks again.Ian
That looks pretty horrific!
Are you quite sure that there is not an air bleed screw on the top of the top fitting?
Using black iron fittings like that is asking for corrosion blockages!
Its not clear to me just what the cylinder is made of. It may collapse if you started unscrewing any of those parts.
If its not a bleed screw at the top then I suppose you could risk unscrewing the smallest plug at the top a few turns and see if air comes out.
But at the end of the day its probably blocked and a very difficult scenario to even contemplate any work on!
Tony
Are you quite sure that there is not an air bleed screw on the top of the top fitting?
Using black iron fittings like that is asking for corrosion blockages!
Its not clear to me just what the cylinder is made of. It may collapse if you started unscrewing any of those parts.
If its not a bleed screw at the top then I suppose you could risk unscrewing the smallest plug at the top a few turns and see if air comes out.
But at the end of the day its probably blocked and a very difficult scenario to even contemplate any work on!
Tony
Yea I know it looks bad the tank is copper with a insulation foam sprayed onto it,the system was put in 35years ago. The only other thing was the back boiler in the fireplace which only heats hot water is not heating anything another air block I thin,k any ideas how to shift it or are the two problems connected.Ian
Hi Tony,just to let you know got HW going,disconnected every pipe, blowed
down sucked up and eventually it got going,still no HW from back boiler but that can wait for another day.Many thanks you made me look further and gave goos advice many thanks Ian
down sucked up and eventually it got going,still no HW from back boiler but that can wait for another day.Many thanks you made me look further and gave goos advice many thanks Ian
does this mean you are using the immersion heater or are you a little confused!
Mike,i dont know what you mean, I have sorted the air block in the HW side of the CH problem solved. The only problem I am left with is the back boiler in the fireplace which has nothing to do with the CH has an air block, then I have to replace the immersion heater as it has now blown,god I love to be busy,not.
You would be a little confused if you had spent 3 days trying to solve this problem thanks anyway Ian
You would be a little confused if you had spent 3 days trying to solve this problem thanks anyway Ian
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