Mixer Tap Shower Temperatures

[Stuart Young]

Recently had a combi boiler fitted to do away with the hot water tank and pump under the bath for the mixer tap shower.
Even when adjusted full im only getting a warm shower. I've read an old post on here and carried out the relevant checks.
Hot and cold are plumbed into the correct side and ive adjusted the valve on the cartridge to maximum which changed it from lukewarm to warm when on maximum.
On my old setup with the hot water storage tank I used to get a really hot shower when not even on maximum setting. I dont remember what the stat for the old tank was set to.
The hot water from the combi is really hot right up until it enters the mixer tap.
My only conclusion is that the hot water from the old set up was a lot hotter than the maximum from the new combi boiler.
Or possibly that the mains water pressure not being as high as the pressure from the old pump set up then less hot water getting through.
Im also thinking that the cartridge might need cleaned or maintained in some way but thats too much of a coincidence as there were no issues temp wise until the boiler was changed.
If this is sonething I have to live with then can you buy cartridges that have a more hot water biased valve?
Any ideas or input very welcome.
Thanks and apologies for a post which has been part covered before.

 

[footprints]

A thermostatic shower should really cope, but are both hot and cold from the mains? Worth restricting the cold supply a bit if there is an isolation valve under the bath.

 

[Stuart Young]

A thermostatic shower should really cope, but are both hot and cold from the mains? Worth restricting the cold supply a bit if there is an isolation valve under the bath.

Thanks. All water is from the mains supply. There are isolation valves on both hot and cold under the bath.
Excuse my ignorance. I thought isolation valves had to be either full shut or full open.
Is it safe to shut the cold one over a little?
Thanks again.

 

[cross thread]

if the hot at the taps is ok ,i would suspect faulty shower valve

 

[lostinthelight]

Thanks. All water is from the mains supply. There are isolation valves on both hot and cold under the bath.
Excuse my ignorance. I thought isolation valves had to be either full shut or full open.
Is it safe to shut the cold one over a little?
Thanks again.

If you turn the valve down it could make it noisy, I did that after I had my unvented system and the noise drove us mad...ended up fitting a pressure reducing valve

 

[flameport]

Im also thinking that the cartridge might need cleaned or maintained in some way but thats too much of a coincidence

Not really - with a new boiler installed pipes would have to be cut, soldered, etc.
Not impossible that some debris got into the pipes and has partially blocked the shower valve.

 

[Stuart Young]

if the hot at the taps is ok ,i would suspect faulty shower valve

Im suspecting that as the hot at the taps and right up to the mixer tap is ok.
It just seems like too much of a coincidence for me that right up until the combi was fitted i was getting really hot water through the mixer ok.
So im thinking its either the mixer tap cartridge has went faulty somehow during the combi installation or the combi just isnt giving out water as hot as what i was getting from my old hot water storage tank set up and the hot/cold ratio in the mixer, even when at maximum hot isnt enough.

 

[Stuart Young]

Not really - with a new boiler installed pipes would have to be cut, soldered, etc.
Not impossible that some debris got into the pipes and has partially blocked the shower valve.

You're right. Thanks I overlooked that.
I don't have any experience with these cartridge valves. From what I've seen online they can normally be removed and cleaned and put back in. Is that correct?
Also the mixer shower is around 10 years old. Would if be better to have replacement seals etc at hand?

 

[footprints]

Thanks. All water is from the mains supply. There are isolation valves on both hot and cold under the bath.
Excuse my ignorance. I thought isolation valves had to be either full shut or full open.
Is it safe to shut the cold one over a little?
Thanks again.

It's fine to turn down an isolation valve, as said sometimes they get noisy, the main thing is if it cures it you know it will work and can try other means of reducing pressure. It will only whistle while you are in the shower if at all so the shower noise tends to cover it.

 

[Stuart Young]

It's fine to turn down an isolation valve, as said sometimes they get noisy, the main thing is if it cures it you know it will work and can try other means of reducing pressure. It will only whistle while you are in the shower if at all so the shower noise tends to cover it.

Cheers!
I'll give that a try.

 

[dilalio]

Also the mixer shower is around 10 years old.

Then it's done well to last that long. If it's a decent, known brand you should be able to get a replacement flow and/or thermostatic cartridge but be prepared for high prices if its a concealed unit, if its exposed then you'd be better off replacing it.

You could try removing the current ones and giving them a wash. Also flush out the valve while they're removed and try and catch the water so you can see if any detritus comes out of the pipes.

And clean any inlet filters/strainers.

 

[Stuart Young]

Cheers for all the help!!!!