Indirect water cylinder not heating water properly

[RM2023]

Hi,

I'm having an issue where the water from our water cylinder comes out lukewarm, maybe even colder than that to be honest. From what I've seen online, I think the water cylinder is an indirect unvented one and has always been powered by our boiler.

The water cylinder is in the airing cupboard on the 1st floor and the boiler is on the ground floor. When the boiler comes on to heat up the water, it only comes out lukewarm. Not even warm enough for a shower. If we use the immersion heater, the water comes out much hotter, but still not as hot as what it used to be. The radiators which are also powered by the boiler and seem to work fine, there doesn't appear to be any issues with them.

Just for context, I recently went away for a couple of weeks. Before I left, I was told to turn the stop cock off. I can't say it's something I've ever done before, but there was no issue with the water before I did this.

I've added some photos of the water cylinder and the pipes next to it.

Any help would be appreciated, thanks in advance

 

[Exedon]

I take it heating system is properly pressurised?
Have you made sure no air in heating cylinder feeds?
Loosen small brass caps on pipework on top of cylinder to check.
Other than that make sure motorised valve to cylinder is open
That's the silver one manual lever should feel loose when open.

 

[RM2023]

Hi Exedon, this is probably going to sound stupid, but how would I know if the the heating system is properly pressurised? I can't see any pressure gauges on the cylinder or the boiler, unless they're tucked away/hidden somewhere.

I've given the cylinder feeds a go. The left one had the smallest amount of air come out of it, and the right one had water coming out of it straight away. Not sure if the left one will solve the issue - fingers crossed.

I've tried the motorised valve you said about too. It was set to the auto setting, but i've now slid it across to open - albeit it only goes halfway. It moved easily to the halfway point and then i got resistance. I didn't want to put too much force into pushing it all the way to open in case i broke it. I'll try to get a photo to show you what i mean.

 

[oilhead]

If your system is an open system you will have a header tank in the loft, Check that this has water in it.

 

[RM2023]

Exedon - stupidly i tried the motorised valve when the boiler wasn't on. Now it's on, the lever slides between auto and open easily.

Oilhead - i've just checked, there is. It's a bit grotty though, not sure if that'll make a difference.

 

[RM2023]

Exedon - your suggestion worked. It was beautiful to have hot water this morning

Thanks again