rising main water temperature

[Bill Wright]

Ours is 5.7C. Anyone else checked theirs?

Bill

[tabbypurr]

that's typical temp in winter. In summer nearer 10C

NT

[spuorgelgoog]

No, but you've reminded me to put the immersion on for a bath. I don't think the electric shower will be very wonderful.

Owain

[GB]

So, for the same flow rate, an electric shower will be 4C lower in winter than summer. That's probably noticeable, but the flow rate would only need to be reduced by about 10% to get the same temperature in winter.

I'm sure Owain's comment (below) is correct, but why?

"you've reminded me to put the immersion on for a bath. I don't think the electric shower will be very wonderful."

[GB]

So, for the same flow rate, an electric shower will be 4C lower in winter than summer. That's probably noticeable, but the flow rate would only need to be reduced by about 10% to get the same temperature in winter.

I'm sure Owain's comment (below) is correct, but why?

"you've reminded me to put the immersion on for a bath. I don't think the electric shower will be very wonderful."

[Harry Bloomfield]

It happens that Bill Wright formulated :

I make ours, 2.7C. It comes from a water tower, so perhaps extra cool.

[Bill Wright]

Ours comes from a buried reservoir.

Bill

[Harry Bloomfield]

[e-mail] formulated the question :

My electric shower copes perfectly well. Its a 'set the temperature you want' type and it does what ever it needs to do to match the setting.

[Harry Bloomfield]

Underground, it will be a tad warmer.

[NY]

When our shower element failed and was deemed non-repairable, we had to get a new shower. The electrician would not fit one that was as powerful as we'd had before because of the grade of cable that had been used - and replacing the cable would have meant trying to lift the floorboards in the loft that the previous owner had *glued* down as well as screwing them down.

The new shower (9 kW rather than 12 kW) was just about OK in the summer, but on a freezing cold day like we've been having recently, it was impossible to get more that a piddly trickle if you wanted the water any warmer than tepid.

[Gordon Henderson]

My thermapen showed 3.5°C this morning (Southern edge of Dartmoor).

(I run a home-based microbakery and water temperature is something that interests me)

Gordon

[Jethro_uk]

When we had a chance to refit the bathroom, the shower was the first thing to be replaced, it was the most powerful in the Triton range (11.xKW) and I fitted an appropriate cable in the loft. Which was fun to try and bend. I still have 25m of it left - weights a tonne.

That meant I had to upgrade the fusebox to one with an RCB ...

After all that, it's a question of "was it worth it ?". SWMBO has baths anyway (until we refit again and make a wet room). It's acceptable in summer, but in winter to get a decent temperature, you have to reduce flow to a light sprinkle.

If I had more showers at home, it might be a priority, but as I'm swimming most days, I can wait.

[Scott]

My flat was 17 degrees with the heating off. Does this mean my downstairs neighbour can expect a large gas bill :-)

[Harry Bloomfield]

NY was thinking very hard :

Mine is a 9.5 or 10Kw, not sure without checking, but I find it more than adequate. It still has good flow, even when set far too hot. Guess I must be made of sterner stuff. Its 'adjust the flow, to get the temperature' 7.5Kw predecessor was not really adequate at all, it needed constant adjustment to keep the temperature right.

Just dial in 5 on the temperature setting, push the button and its fine, even in this weather.

[John Rumm]

Because you set the temperature required, and have to live with whatever flow rate is necessary to achieve that. Hence with colder water incoming you will get a weedier shower.

Have a look at the flow rate comparisons in the table:

[Max Demian]

When I had an electric shower I always had to switch it to the high power setting in winter.

[Max Demian]

How long was it off?

[GB]

But, that table allows for a much bigger temperature difference between summer and winter. We are being told that the incoming main is 5.7C at this very cold time of year, and "nearer 10C" in summer. That's a difference of only 4C, and it takes a flow difference of only 10% to correct it (for a 40C shower), which is what I said above. I think 10% is scarcely noticeable.

The table you quoted assumes a 10C difference in the incoming mains temperature between summer and winter. I'd therefore expect a difference in flow rate of 25% in that table, whereas it actually quotes 29%. I am not sure where the extra 4% comes from, but I'm not going to quibble. A

29% reduction in flow is probably noticeable, but not a complete game changer.

I suspect that there are other factors in play, for example maybe we want warmer showers in winter than summer because the bathroom is colder. So, maybe the answer is to heat the bathroom more, rather than install a more powerful electric shower with all the cabling required?

[Roger Hayter]

I think you are right. When we designed our wet room we decided to have an electric shower (9.5kW) as two showers on a combi boiler seemed a dubious plan. We have electric UFH which is always on, keeping the lfloor at about 25 degrees C, and central heating (fan assisted radiator) on during the ten cold months of the year. We find that, although we need slightly dfferent flow settings (flow controlled shower rather then temperature controlled), subjectively the shower is little different in flow and temperature in the winter. May seem a luxury, but since the shower room is the only properly insulated bit of the house, on five out of six sides at least, it is relatively cheap to heat.

[GB]

I'm being dense: 25/35 = .71, ie 29% reduction.