Any plumbers - help please!

[HKW81]

Our hot water isn't running as hot as it should, even when it's on maximum in the shower it isn't that hot and running a bath the other day wasn't hot enough to sit in. The waters hot but not hot enough if you see what I mean (admittedly I do like scalding showers!!)

I'm sure a couple of years ago when we had the plumber in he said it was the water pressure, turned something and he fixed it. Does anyone know what he will have turned and which way? Stopcock? It was so easy I thought I'd give it a try myself before ringing anyone!

Thank you in advance 😌

@PigletJohn usually knows about this stuff :) Is he here anywhere? Calling PigletJohn!

I bet you've got a combi.

"They all do that" (when it's winter and the incoming supply from the watermain is colder).

Let's suppose the boiler can heat the water by 40C

And in winter the watermain is 10C colder than in summer

So the winter hot tapwater will be 10C colder.

Summer 15C up by 40C is 55C
Winter 5C up by 40C is 45C

Turn down the tap and fill the bath slower and the water will be hotter.

Thank you!! Yes it's a combi. I'll try that with the bath. Any ideas how to make the shower hotter please it will we just have to get used to it?! Thanks again 😌

You could try a water-saving head or jet. Often available free from your water company.

Example
www.stwater.co.uk/wonderful-on-tap/save-water/free-ways-to-save/

PigletJohn, you have just deterred me from ever replacing my trusty 20 year old Ideal Mexico with a combi boiler! Why on earth can’t you just turn up the water temp on the combi?
My old boiler has a simple control knob - you can set the hot water tank temperature to anything from tepid to scalding, and the radiators have individual thermostats.
Is this beyond modern technology to provide?!

A combi can heat X amount of water by Y degrees in T amount of time.

Fix T as one minute, and it could notionally heat 12 litres by 40 degrees, or 6 litres by 80 degrees, or 24 litres by 20 degrees (in fact the variations are smaller than that).

A hot water cylinder can deliver stored hotter water, by taking longer to heat from cold (e.g. 40 minutes instead of 30) in winter when the incoming water is colder so T has increased although you will probably not be aware of it. On a combi you increase T by running the tap slower.

Old or new technology works to the same rules.

Modern cylinders and boilers are generally better than old ones; hold more water, heat faster, have more power, so don't be misled into comparing a good modern system of one type, with an antiquated system of a different type, and thinking that the "different type" explains all the differences in performance and efficiency.

But surely running the tap slower means that a) you have to hang around longer waiting for your bath and
b) the already delivered bath water itself is losing heat to the bathroom air while it sits longer in the bath waiting for the rest of the water to slowly trickle in?
My ancient boiler heats an insulated tank to whatever temp I want and keeps it there. I can run it hot and fast whenever I like.
The modern combi doesn’t seem to be able to match that, from what you are saying. And that’s without all the problems with condenser flues and water pressures, and planned obsolescence. I don’t see many combis being sold with 20+ year guarantees!

modern combis are often very powerful, around 30kW, so they can deliver a good shower and fill a bath in a tolerable time.

There are other people who will sing their praises.