Mixer tap not mixing correctly

[amateurSparky]

Hi

I am having a problem with the mixer tap in the bathroom. When I turn the tap all the way to the right I should get hot water (pipes are reversed) but instead I get no water at all. When I turn the tap slightly to the right I get slightly warm water. If I turn the tap all the way to the right I get cold water.

Here is a video of the problem

VID-20250717-WA0001.mp4

drive.google.com

I don't have boiler so the hot water comes from the mini heater. I have attached an image of the heater

 

[CountryFan]

Can you start by stating what type of setup you have? Eg combi boiler, traditional type et al. Also, any isolation valves fitted below? If so, Have you tested these to ensure they’re open fully?

 

[avonmouth]

Has someone changed the cartridge in that tap lately ?
My money is on the cartridge being faulty or fitted wrong.

 

[Scally-Ho]

OP has already displayed his Ariston Titanium Plus water heater, but has not stated it's Kw loading yet. The reverse connected mixer does not bode well for the installation.

 

[amateurSparky]

I don't have a combi boiler. I have a small water heater beside the sink. I attached an image of what I mean to the original post. The isolation valves under the sink are fully in the vertical position ( the one you need a flat head screwdriver to operate)

I have attached a picture of the label

 

[amateurSparky]

OP has already displayed his Ariston Titanium Plus water heater, but has not stated it's Kw loading yet. The reverse connected mixer does not bode well for the installation.

Hi what do you mean the reversed connected mixer does not bode well? What difference does it make? Do you mean it doesn't give a lot of confidence in the installer know what he was doing?

 

[Scally-Ho]

Mixers are designed to work in one flow direction and to reverse that direction is not a recommended installation practice.

 

[amateurSparky]

Has someone changed the cartridge in that tap lately ?
My money is on the cartridge being faulty or fitted wrong

Sorry could you explain to me what the cartridge is and what it does? Is it easy to replace? I don't think any work has been done to it.

 

[CountryFan]

OP has already displayed his Ariston Titanium Plus water heater, but has not stated it's Kw loading yet. The reverse connected mixer does not bode well for the installation.

That wasn’t displayed when I replied

 

[CountryFan]

The isolation valves under the sink are fully in the vertical position ( the one you need a flat head screwdriver to operate)

You need to verify that they’re open fully, just because they look open, doesn’t mean they are.

 

[Madrab]

Can you take the plastic bags off of the heater and re-do the pic. There is PTFE tape around the threads of the connections which invariably is a DIY red flag.

One other reason why there's no output when fully right is that only one side of the tap is actually connected.

 

[bernardgreen]

The hot and cold have to be supplied to the correct ports on the mixer.

If the water coming out of the mixer is colder than the required temperature then the thermostat will further close the cold inlet and further open the hot inlet. With the connections reversed opening the hot inlet will allow more cold water through the mixer.

 

[Madrab]

It's a monobloc basin mixer tap with a ceramic cartridge, it's not thermostatic.

 

[ChrisJP]

Hi

I am having a problem with the mixer tap in the bathroom. When I turn the tap all the way to the right I should get hot water (pipes are reversed) but instead I get no water at all. When I turn the tap slightly to the right I get slightly warm water. If I turn the tap all the way to the right I get cold water.

This is confusing. The 2nd sentence says you get no water at all when the tap is turned all the way to the right. But then the 4th sentence says that when the tap is turned all the way to the right you get cold water. So which is it?

 

[Madrab]

Take a look at the vid - tap flows until the lever is just past mid point to the right, flow then stops. So either the cartridge is goosed or one of the feeds isn't connected.