Can't heat enough hot water

[Cfman22]

Hello,
New to the forums.
I had a new hot water tank (135l), vortex oil boiler and down stairs, upstairs and hot water booster controls fitted.
I can control the heating of the radiators for the downstairs, upstairs and supposedly the hot water for taps and showering.
However I also have an in tank dual Immersion heater too.
During this time of year in not running the oil fired central heating but whenever I run the Immersion for say an hour, it doesnt seem to do a whole lot. I can shower and even take somewhat of a bath (not too full).
I understand that the water in the tank isn't being heated from the central heating so the Immersion needs to run for longer to heat up the body of water. However if I leave the water for an hour or so it seems to cool down. Is this normal?

I also mentioned that I have the option of using the oil fired burner to heat water and if I run it for a while it seems to just heat the upstairs radiators which isn't ideal in the summer.
Is that normal for it to heat the radiators if I only want hot water?
All the work was carried out by a heating plumbing contractor before Christmas as part of a heating upgrade grant.
It seems to have some bugs and was just wondering if anyone had any insights into this?
I will contact the company who did the work as I'm sure it's warranted.
Thanks

 

[Deleted member 120897]

Sounds like there’s a piping fault or wiring fault to the oil boiler setup, and if you’re only running one immersion, then it’ll deplete fairly quickly, but depends on cylinder size, insulation etc.

 

[John.g]

The (bath) immersion will heat around 120L, to heat 120L from say "cold" at 25C to hot at 60C will take almost 2 hrs assuming a 2.5kw element, it will only heat 120L to ~ 43C so run or time it for 2 hours, the thermostat will cut off the power in any case even if you leave it on for longer than 2 hrs.
Re boiler not heating the cylinder, check that your timer/programmer has 3 zones including one for HW, if you have (or have not) then get your heating engineer back to fix the problem.

 

[Basher]

You mention dual immersion heater and 'booster controls'
Is that two immersion heaters at different positions in the side of the tank (eg one near the bottom and one half way up), or is it a single unit mounted in the top of the tank, pointing downwards, with one long element and one short element?

With a 135L tank you need to be energising the lower immersion, or the longer one if top mounted, not a 'boost' one, if you want a full bath or a decent shower. So is there a way to energise the "whole tank" (lower - not boost) immersion?

I would have thought it might take more than an hour to heat the whole tank from cold. Can you feel how far down the tank gets hot if you put your immersion on for a couple of hours?
Edit: John G you've covered that! - I was thinking OP was relying on a 'boost' button, which for a dual immersion will not heat the whole tank!

 

[Cfman22]

You mention dual immersion heater and 'booster controls'
Is that two immersion heaters at different positions in the side of the tank (eg one near the bottom and one half way up), or is it a single unit mounted in the top of the tank, pointing downwards, with one long element and one short element?

With a 135L tank you need to be energising the lower immersion, or the longer one if top mounted, not a 'boost' one, if you want a full bath or a decent shower. So is there a way to energise the "whole tank" (lower - not boost) immersion?

I would have thought it might take more than an hour to heat the whole tank from cold. Can you feel how far down the tank gets hot if you put your immersion on for a couple of hours?
Edit: John G you've covered that! - I was thinking OP was relying on a 'boost' button, which for a dual immersion will not heat the whole tank!

Thank you for your replies, I think it's expected for my 135l insulated tank to take about an hour to heat up to a usable level for a bath.
I don't run the central heating this time of year so I'm dealing with ambient temperature water in the tank.

Apologies Basher I should have been clearer about the Immersion set up. My Immersion heater is a single unit that has 11" and 24" elements beside eachother and it's installed on the top of the tank.

It does indeed need an hour or more to heat the water sufficiently, it's just I wanted to check with experts especially since the price of electric has gone through the roof and I only have the Immersion and oil central heating to heat the house.

I have 3 wireless EPH thermostat controls, 1 for downstairs, 1 for upstairs and 1 in beside the hot water tank for supposedly heating hot water. I have an EPH timer/controller for the oil burner that communicates with the wireless thermostats.
I don't use the 7 day timer for heating, rather I decide to heat the house as and when I need. I can also use the ember app to control the heating remotely but this has stopped communicating.

My question is should i be getting hot radiators if I'm just trying to heat hot water by activating the zone for the hot water tank?
I would have thought the water in the tank would be heating only and not the radiators?
All the work is only a few months old and I used to only have 1 zone for the whole house with a valve to heat the hot water separately which I'm not sure worked prior to me buying the house.
However I can see the in tank water temp on the EPH controls screen and it does seem to increase but only when I run other zones. The installer said that they were able to zone my house as all the pipes were in the one areas and a 3 way valve would work.
I was paranoid for a while as I'd activate the upstairs thermostat to heat the upstairs but it would heat the downstairs radiators and vice versa.
I ended up swapping the wireless thermostats from upstairs to downstairs and this seems to have fixed the radiator heating mix up. I wonder has the EPH controls used in the house caused an issue with me trying to use the oil central heating to hot water.
It's a really weird and frustrating problem.

 

[ShaunCorbs]

No something is wrong you should be able to use one zone at a time with the others not heating get the ones who did the work back to check there side

 

[John.g]

You will/should have 3 of 2 way motorized (zone) valves. Ensure everything switched off and stand by the cylinder valve then get someone to operate each zone on for 30 secs or so then off and see which one opens the cylinder M.valve, if you can't hear it operating you can feel a lever on the side or bottom of the M.valve, actuator,when de energized you should feel a fairly stiff resistance when pulling it open, if energised the lever will have no resistance when you pull on it.

Also, when you operate the HW zone valve see if its opening the upstairs zone valve as well.

 

[Murdoch]

Re the immersion heaters - you say you have 2

Are they both wired up?

 

[John.g]

If its a top mounted Dual Immersion then should look like the attachment(s) but maybe Dual Immersion in the above actually means two immersions mounted at different cylinder levels.