Cold/Luke warm water from Hot Taps

Deanicus

Hi,

I know this question/problem has been asked a lot before. I read a lot of older threads but still couldnt find a solution.

I noticed recently that the hot water in the house hasnt been very warm. It started off as being hot but not hot enough to cause you to pull your hand away. We are usually only there at night and I always thought it was because we didnt have the heating on very often. Then the last few days it barely got above luke warm if at all. Its probably related to the bad weather but I thought I would check.

The heating is working fine and water is running in all hot taps in the house but even with the heating been on for hours on end the water is barely warm.

I did turn the odd valve or two in the hot press and see if that did anything. I returned them to their original positions afterwards but maybe I did something wrong.

I have attached a picture of the hot press set up.

Can anyone out there help me? I am completely ignorant to plumbing.

Cheers

ntpm

If the heating side is working then you may have a flow problem through the coil of the cylinder.

I am assuming that when you switch your boiler on you can individually switch off heating to upstairs and down stairs ( zones) and have hotwater only. if so then:
The higher red hand valve looks like a bypass valve.
This should be slightly (cracked) open. If it's opened too much the hotwater will by-pass your cylinder. The cylinder coil wont get enough flow hence colder water temp.


Also check the following things:

1. The thermostaic cylinder stat on the flow pipework into the cylinder ( white head stat ) may be stuck.
FYI. This opens and closes the valve depending on the temperature sensed by the phial attached to the side of the the hot water cylinder).
Remove the head and press down the the pin. (Normally with the head taken off the valve should be fully open).

2. The lowest red hand wheel on outlet of the cylinder coil/ return pipe needs to be at least half open to fully open. (Turn anti-clockwise to open).

3. There may be air in the heating coil. Check the automatic air vent is open. This is the brass fitting top left of ypour pipework. Open the small fitting on the top off it. Some air may hiss/ come out.


4. Check your filling valve. This should be fully closed at all times.
The pressure gauge indicates the pressure in your system and if you have a leak then it will drop.
This should only be opened to re-pressurise the system to 1-1.5 Bar after venting or refilling system.

Sparkpea

matter of trial and error

first thing is take the white thermostatic head off the cylinder stat, once u take it off theres a metal pin inside push it in and out a couple of times, run your heating for a good 60-90mins, check hot water. if its better then you need a new stat head.

Snaggerman

Sparkpea wrote: »

matter of trial and error

first thing is take the white thermostatic head off the cylinder stat, once u take it off theres a metal pin inside push it in and out a couple of times, run your heating for a good 60-90mins, check hot water. if its better then you need a new stat head.

Just wondering, as I have a similar problem, should this pin be up or down, TIA

Sparkpea

if the pin is out, the valve is open full, pushed in is closed

joxers25

Hi Guys,

I have similar issue and have attached a diagram of setup. Only have luke warm water from hot taps.

Have to use immersion for showers etc, expensive.


notes

Was working fine until our water got cut off, after tank emptied and our water pressure was down to 0.0

The water returned the boiler returned to 0.1 (not sure what it was previous) and the gas wouldn't come on

We called bord gas as we were due for a service anyway. The engineer that arrived simply bridged the connection and carried out the service.

The gas then came on and pressure built to 0.5, but returned to 0.1 when the system was off.

Any help appreciated.

Sparkpea

top right of the pic looks like an automatic airvent that probably has a black dust cap on it, check its not on tight, it should be left loose to let air out. could be airlock in the flow pipe. those pipes going into the tank you've labelled hot and cold are actually flow (top) and return (bottom) and the valve on the bottom should be open about half way.

you need to top up your pressure to about 1bar and it will rise to maybe 1.5bar when heat is on. can you take a pic of around your gas boiler?

joxers25

Sparkpea wrote: »

top right of the pic looks like an automatic airvent that probably has a black dust cap on it, check its not on tight, it should be left loose to let air out. could be airlock in the flow pipe. those pipes going into the tank you've labelled hot and cold are actually flow (top) and return (bottom) and the valve on the bottom should be open about half way.

This worked thanks Sparkea!

you need to top up your pressure to about 1bar and it will rise to maybe 1.5bar when heat is on. can you take a pic of around your gas boiler?

photos attached - thanks again.