Poor Heating

[Tony 1]

For some reason all of a sudden the hot water and central heating is not getting as hot as it used to. At one point you could not keep your hand on the radiators for more than a couple of seconds or under the hot tap but now you can. It has also affected the shower as well. My system has two water tanks in the loft and and a water cyclinder in a cupboard. I have adjusted the thermostat on the cyclinder but nothing has changed. It is warm but not as hot as it used to. Any ideas of what is causing this and is there anything that i could check?
Thanks

 

[D_Hailsham]

For some reason all of a sudden the hot water and central heating is not getting as hot as it used to. At one point you could not keep your hand on the radiators for more than a couple of seconds or under the hot tap but now you can. It has also affected the shower as well. My system has two water tanks in the loft and and a water cyclinder in a cupboard. I have adjusted the thermostat on the cyclinder but nothing has changed. It is warm but not as hot as it used to. Any ideas of what is causing this and is there anything that i could check?
Thanks

Crystal ball time again

I see a pump, possibly Grundfos, is it working? I put screwdriver against pump and other end in my ear? Can I hear the pump whirring? Yes; then the pump is probably OK.

I see a motorized valve with three ports or is it two 2-port valves? Do these valves open and close when I turn the tank and wall stats up and down? (I can't see them move but I can hear them.)

I see a boiler. Does it light when I turn the tank/room stat up and is the flame as large as usual?

Thought ; it's getting much colder. I wonder if the boiler is actually up to the job of keeping the house warm. If it's not big enough the rads will never get up to temp.

Another thought , when did I last have the boiler serviced? Er, wot that, guv?

 

[bengasman]

Some more details would not go amiss, but when I read cylinder, little bird whispers in my ear: open vent, probably full of krap due to lack of maintenance.
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