HIU - Hot Water Billing

Craigdav1993

Hello everyone!

We moved into a new build flat in March 2021 and the heating/hot water is provided through an HIU which is connected to a main boiler in the basement, basically central heating where each flat is billed for usage and the HIU keeps water hot ready to go.

Our first bill was a bit of a shock considering we have 1 shower each for 5 minutes a day (occasionally 2), dishwasher and washing machine both use electricity to heat the water up and we used the heating 3 times in six months for 20 minutes (an hour in total)

Its two of us and we have been billed £305 for 6 months of hot water only (excluding Water Supply) at 11p (£0.11) per kWh.

I started monitoring the HIU meter and noticed for a 5 minute shower it used 13 kWh of hot water (costing us £1.43 for one shower)

The meter was showing the current usage was 101 kWh / h and 1.722 m3/h whilst the shower was running.

From other people experiences, is this usage normal with our usage standards, do you think there is something wrong or does it all sound good?

I find 101 kWh and a 5 minute shower at £1.43 pretty expensive considering you add water and electricity to run the HIU too.

Any feedback, experiences and ideas would be greatly appreciated!

Thank you  

Craigdav1993

Here are the readings whilst the shower was running.

Gerry1

Craigdav1993 said:

Its two of us and we have been billed £305 for 6 months of hot water only (excluding Water Supply) at 0.11p per kWh.

Is it really only a whisker more than a tenth of a penny per kWh?

Did you read the meter yourself when you took possession of the property?

Craigdav1993

Gerry1 said:

Craigdav1993 said:

Its two of us and we have been billed £305 for 6 months of hot water only (excluding Water Supply) at 0.11p per kWh.

Is it really only a whisker more than a tenth of a penny per kWh?

Did you read the meter yourself when you took possession of the property?

Apologies I mean 11 pence per kWh (£ 0.11 per kWh)

Yes when we moved in the reading was 1829 kWh and the current reading is 4550 kWh. Total usage was 2721 kWh since 1st of March 21.

The images provided are the live usage of hot water from the meter.

Gerry1

You're certainly being ripped off at 11p/kWh when mains gas is available at under 4p/kWh.  You'll make some savings because you won't have the capital and servicing costs of your own boiler, but presumably you're paying via the flat's service charges?

Unfortunately there's no competition when you're on a heat network and not much consumer protection.

Best to consider moving if you're renting.

Craigdav1993

Gerry1 said:

You're certainly being ripped off at 11p/kWh when mains gas is available at under 4p/kWh.  You'll make some savings because you won't have the capital and servicing costs of your own boiler, but presumably you're paying via the flat's service charges?

Unfortunately there's no competition when you're on a heat network and not much consumer protection.

Best to consider moving if you're renting.

Absolutely! Sadly we fought hard to find out exactly the cost per kWh and the exact type of system, but as we were the first people to move into the building vague answers were given.

We only managed to finally find out the unit cost per kWh after nearly 6 months when we received our first bill. We sent numerous emails and were always told we’d get the info shortly.

Luckily we saved monthly and took an average cost of £50 a month into account for heating which is actually less than what we’re being billed, and that is in summer with no heating!

I am just worried about the meter showing 101 kWh / h usage whilst the shower is running 😳 that sounds out of proportion for one shower running and all taps off.

Sadly as the heating/hot water is central heating we are billed directly from the building management through a third party metering company and are unable to switch suppliers like we did with electricity.

Gerry1

Craigdav1993 said:

Gerry1 said:

You're certainly being ripped off at 11p/kWh when mains gas is available at under 4p/kWh.  You'll make some savings because you won't have the capital and servicing costs of your own boiler, but presumably you're paying via the flat's service charges?

Unfortunately there's no competition when you're on a heat network and not much consumer protection.

Best to consider moving if you're renting.

I am just worried about the meter showing 101 kWh / h usage whilst the shower is running 😳 that sounds out of proportion for one shower running and all taps off.

The kWh usage may not be as bad as it seems because you are effectively using an instantaneous figure.  An instantaneous electric shower is around 10kW so your 101kW figure probably won't be sustained.  Your figure may closer to 20kW because you have a relatively high flow rate but at a genuine 101kW you'd be scalded by superheated steam !

Therefore you might find that there's enough hot water left for several more showers without the meter clocking up more usage.  It's a bit like a car's fuel economy meter showing 15mpg while you're accelerating or climbing a hill but then showing 99mpg when you're coasting downhill.

QrizB

Craigdav1993 said:

I started monitoring the HIU meter and noticed for a 5 minute shower it used 13 kWh of hot water (costing us £1.43 for one shower)

The meter was showing the current usage was 101 kWh / h and 1.722 m3/h whilst the shower was running.

From other people experiences, is this usage normal with our usage standards, do you think there is something wrong or does it all sound good?

That does sound an outrageously high amount of energy for a 5-minute shower. If you consider a "good" shower to need 10 litres per minute, a 5 minute shower is 50 litres of water. Even with a supply at zero (so meltwater from a glacier, say) and a shower at 40C that will only need (50 litres * 1000 g/litre * 4.2 J/g/C * 40 C = ) 8.4 megajoules of energy, a little over 2.3 kWh.

Is this some sort of super-duper multi-jet shower or a bog standard rose-on-a-hose sort of offering?

Does your HIU actually store hot water or is it an instantaneous heat exchanger, with cold water being heated on demand? (I'm guessing it's the latter.)

Craigdav1993

Thanks for the replies!

so the HIU basically keeps some water hot ready to be served, the hot water is constantly supplied by boiler room in the basement of the building and the HIU keeps some hot ready to go.

the shower is a standard shower head with standard pressure (handheld shower head).

I am just terrified to see my bills for the winter period when we’ll be needing some heating!

Just wanted to check wether any of you recommend an engineer from the meter company coming out to inspect or not.

Forget about asking the management, the maintenance guy that lives in the building had no clue how it works and had a few issues with management abusing power and ignoring genuine complaints over the last year.

Thanks for all the feedback!

QrizB

In your first post you said:

Craigdav1993 said:

Hello everyone!

We moved into a new build flat in March 2021 and the heating/hot water is provided through an HIU which is connected to a main boiler in the basement, basically central heating where each flat is billed for usage and the HIU keeps water hot ready to go.

Our first bill was a bit of a shock considering we have 1 shower each for 5 minutes a day (occasionally 2), dishwasher and washing machine both use electricity to heat the water up and we used the heating 3 times in six months for 20 minutes (an hour in total)

Its two of us and we have been billed £305 for 6 months of hot water only (excluding Water Supply) at 11p (£0.11) per kWh.

Is there any standing charge or are you only billed per kWh? If you're only being billed for energy used, £305 is around 2800kWh which is high for a 2-person household but not completely unreasonable; roughly 15kWh per day. If 13kWh-per-shower was a typical number, your bills would be twice as much.

The main reason for your bills being what they are seems to be that your heat is quite expensive at 11p/kWh, on a par with E7 electricity and roughly 3x the current price of mains gas.

Robin9

QrizB said:

In your first post you said:

The main reason for your bills being what they are seems to be that your heat is quite expensive at 11p/kWh, on a par with E7 electricity and roughly 3x the current price of mains gas.

But you save on capital cost replacement of boiler, any maintenance or breakdowns ....  (personally  not convinced by that argument) ..........  and also hope the landlord pays his bills and doesn't get cut off !