Problems in getting hot water at home - mixer issue?

[JackZ]

Hello,

For some time now I am having trouble getting hot water in our house. Sometimes the water comes out hot and a few minutes later goes cold and often only luke warm.

Initially I thought it was a problem with our boiler and got a British Gas engineer to come and check it. His conclusion was that all was fine with the boiler. He said that one of the mixers we have must be letting the cold feed push through the system and making the water cooler. (We are getting our water at mains pressure).

We have 3 identical Hansgrohe thermostatic mixers. One of them (on a shower which is not used much) is stone cold even when touching the hot water pipe so I think there is a problem there...

What do you think the problem is? What is the solution? Can I repair this myself or do I need to call Hansgrohe? Is this a common problem?

Thank you for your help!

 

[Agile]

Unless you were very experienced with plumbing ( and not needing to ask here ) then I think that you will need professional help with this problem!

In encounter it about every two months!

Tony

 

[JackZ]

Hi again,

I have often asked questions and been helped on this forum so I wanted to give an update on my problem which is now solved so it may help someone in the future.

The thermostatic mixers are fitted with non-return valves. Usually the pressures of hot water and cold water are not exactly the same i.e. there is an imbalance in the system. Non-return valves prevent the higher pressure water (usually cold feed) to push its way back into the hot water system.

In my case, some debris was preventing the non-return valve from closing. Tiny little stones were causing us huge problems!

I removed the mixer from the wall and dismantled it. The 2 important things were 1) I needed to buy a 10mm allen key and 2) I was told by the guy at Hansgrohe that the valves have a reverse thread so you need to turn clockwise to untighten.

Once dismantled, I dipped both valves in a concentrated limescale remover solution until they were clean. I also put the limescale remover inside the thermostatic mixer. Befre assembling everything back, I ran the water from both the cold and hot feeds on full blast to remove any debris inside the pipe work.

It all seems to be working fine now!

Although the technical guy I spoke to at Hansgrohe was great, I also got an email from them telling me to buy a new cartrige or new valves which would have been lots of money for nothing.

This is typically a problem to be solved by a DIYer who can afford the time to clean the elements.

I hope this helps.

 

[denso13]

Well done. And "professional help" not required after all