Hot tap has no hot water

rimgee97

Hi all, I never had gas central heating in my house before so please try to simplify. I have 2 questions:

1. My new house heats the hot water tap only to luke warm. I tried to find a thermostat on a cylinder but it seems that there is no thermostat. Btw when boiler is on radiators are hot and are producing normal heat.
2. Is there a way to make boiler heat hot water only and turn off the radiators?

House is a 2004 build mid terraced 2 storey house. On a top floor in a master bedroom there is 1 thermostat and 2nd one is on a ground floor hallway.

Sleeper12

Can't offer much help on the hot water but thought I'd mention that cylinder. I would replace it with a fully insulated one as soon as you can afford to. In the mean time get that lagging jacket as tight & snug as you can. You lose a lot of heat from the cylinder

hydrus21

The white thermostatic valve next to the red pressure vessel in the 3rd pic regulates the hot water temp.

Its on setting 5. Can it be turned to a higher setting?

blackbox

That thermostatic valve on the pipe going to the coil on your cylinder should control the hot water temperature. It is set to 5, which should be hot. Perhaps it is faulty or has some debris caught in it. As a first step try turning it each way a few times to try to free it.

hydrus21

On Q2.

Turn down the room thermostat to minimum and determine if you still have hot water but no heating.

magicbastarder

You get hot water when the tank is heated from electricity, yeah?

IIRC there should be a choke valve which determines how much hot water 'bleeds' from the heating to heat the water in the tank?

John.G

https://www.boards.ie/discussion/2058347548/hot-tap-has-no-hot-water

As stated above, the white thermostat (known as a Tapstat) controls the cylinder temperature, there is a capillary tube with a sensing bulb going from this and should be attached to the cylinder, the Tapstat setting (hottest setting 5) then, assuming the boiler flow temperature is high enough, say 60/65C, determines the HW temperature, these tapstats normally fail fully open so unlikely to be this except the valve is jammed partially shut. On the cylinder coil outlet, directly below the Tapstat you will probably see a red wheel gate valve, ensure this is fully open, should be 3 or 4 full turns anticlockwise from fully shut. It looks as if you must have the CH on as well otherwise the boiler won't fire up but easy to check by turning down the roomstats to minimum.

rimgee97

thanks all,

Q1
I will try to turn the tapstat on and off a few times to see if something will change. I will try to fully open the valve under the tapstat as well.

If that wont work; do I have to call gas engineer or a plumber to have a look at the luke warm hot tap issue?

On a 2nd question:

i will turn thermostat in a hallway and in a master bedroom to 8 degrees and I will let youse know tomorrow if that works. If it doesn't what would be the ultimate solution to not having a full blast on radiators in the middle of "summer" if I want to heat my water

thanks all

rimgee97

guys I just want to let youse know that john.g was right and i anti-clockwise turned all the valves in the hot press and the hot water is actually hot now. But I thing that there is no way of heating water only but radiators have to be turned off manually 1 by 1.

thanks all for helping out