Very high water consumption

[JX350C]

Hi everyone,

I moved into a new build three bedroom, two bathroom bungalow about 2.5 years ago. Ever since we moved in there has been an issue with the water pressure.

Toward the end of last year the pressure had got worse. For instance, you could not run another tap in the house if a toilet was refilling or if someone was in the shower. If someone was running a bath then all taps in the house would have no water supply to them and the toilets wouldn't refill if flushed until the bath was stopped.

So we telephoned our water provider to see if this is normal for this area or if there were any known issues with the supply in our street.

To our suprise they said that they have noticed that since we have moved into the property that we have been using very high amounts of water.

I can't see us consciously being users of a large amount of water. We have a shower most days and sometimes have a bath instead. We have a dishwasher and washing machine. The dishwasher is used about once a day and the washing machine is only used maybe twice a week at most. The showers we have are mixer type without any power assistance.

The water company have so far been very helpful and asked us to undertake some simple tests to try to identify either a leak or something else in the house using large amounts of water.

The first thing they asked us to do was to ensure the stopcock in the house was fully open. To my surprise I found the stopcock in the house to be only about half open. I thought that when we moved in that this was all setup correctly. I did check the stopcock before calling the water company but I could not turn it. After checking it again following speaking to the water company I managed to turn it until it was fully open. I think it had got a little seized so just needed more brute force to open it fully. Once I had opened it fully, we had full water pressure and we could use the taps at the same time as running a bath or flushing the toilet. The water that came out of the taps and toilet however was brown for a while and it then settled back to clear water.

So the water pressure issue was resolved.

But the water company stated we were using very large amounts of water so we needed to test for a leak between the meter in the street and the stopcock in the house.

So I fully turned off the stopcock and took a meter reading. I waited an hour and checked the meter again and it had not changed. So the water usage was from something or a leak in the house.

So I turned the stopcock fully open again and started to monitor usage by taking regular meter readings.

To my horror I could not believe the difference between the meter readings. Between the readings we did not use any toilets, showers, didn't have any baths and did not have the washing machine or dishwasher on. We didn't use any of the taps so I thought the readings should not change.

The first meter reading that I took, after opening the stopcock in full, was from overnight and it indicated that we had used 130 litres of water overnight.

I've been doing further readings with the stopvalves to individual items closed and without using any water from taps etc.

Overnight last night we have used 394 litres of water. Again, we did not use any showers, toilets, baths or taps during that time.

So with everything off we were still using lots of water for some reason.

So the only thing left that I could think of was the underfloor heating and water heating that is in our laundry cupboard.

So I switched off all the underfloor heating controllers in each room and ensured the manifold actuators were all closed. I then also switched the hot water controller to off instead of it using the timer schedules.

I took a new meter reading and waited an hour and to my suprise we had now only used 3 litres of water. I left it another hour and took another reading and that time we had used 1 litre of water. However, we did not use any taps or any water during that time so even with the heating and hot water off we still have some form of water leak/usage somewhere.

My first concern is why the underfloor heating and/or water heating is using such large amounts of water. Is it normal for underfloor heating to use so much water when it is on?

The underfloor heating and hot water are fed from an air source heat pump.

The hot water is held in a 200 litre cylinder next to the underfloor heating manifolds. We do not have any water tank in the loft.

I'm now going to test the modern dual flush toilets to see if they are using water when they shouldn't be. They appear to be dry around the pan and I can't isolate them easily because the shutoff valves for each toilet has been boxed in.

Unfortunately our landlord did not provide us with any instructions for this heating system in this house so I'm having to learn it as I go along.

Thanks,

Chris

 

[John.g]

My kingdom for a pressure gauge on the HW cylinder, it would save a lot of hassle and expense for people if it was included as standard on all unvented HW Cylinders.
Your findings are very interesting in that your plumber saw the pressure rising/falling by 1.5 to 2.0 bar to 4.5bar, if, which seems the more likely explanation at the moment, it is flowinng back through the shower & HW cylinder expansion valve then down the tundish then it points to either the E.valve (or the cylinder safety valve) are gone weak and lifting at 4.5bar or the E.valve has been set too low, also if the HW cylinder PRV has been set to 2.8 to 3.0bar then the E.valve could lift each time a big volume of water is reheated, admittedly to only discharge ~ 4 or 5 litres each time. Also loosing say 400L at night through the HW cylinder should mean that the whole cylinder had to be reheated each morning from practically stone cold, did you notice anything strange about the heat up times?

 

[JX350C]

My kingdom for a pressure gauge on the HW cylinder, it would save a lot of hassle and expense for people if it was included as standard on all unvented HW Cylinders.
Your findings are very interesting in that your plumber saw the pressure rising/falling by 1.5 to 2.0 bar to 4.5bar, if, which seems the more likely explanation at the moment, it is flowinng back through the shower & HW cylinder expansion valve then down the tundish then it points to either the E.valve (or the cylinder safety valve) are gone weak and lifting at 4.5bar or the E.valve has been set too low, also if the HW cylinder PRV has been set to 2.8 to 3.0bar then the E.valve could lift each time a big volume of water is reheated, admittedly to only discharge ~ 4 or 5 litres each time. Also loosing say 400L at night through the HW cylinder should mean that the whole cylinder had to be reheated each morning from practically stone cold, did you notice anything strange about the heat up times?

No I hadn't noticed anything about the heat up times. This is the first time we have had this system and the first we knew about a problem was when the water company commented that we are using very large amounts of water.

 

[EvilDrPorkChop]

Well really all the showers etc. mixer taps should of been taken off the Balance cold on the Combination Valve on the cylinder to prevent this. The easiest way to sort this would be either fit a PRV on the incoming main to 3 bar, or fit a Non return valve to the Hot Outlet on the cylinder.

 

[Chuck]

No I hadn't noticed anything about the heat up times. This is the first time we have had this system and the first we knew about a problem was when the water company commented that we are using very large amounts of water.

There's one thing worse than throwing large amounts of water down the drain and that's... throwing large amounts of hot water down the drain! I suggest you read your meter(s) now so you can compare consumption of gas before and after fixing the problem.

Now you've found a decent plumber, make sure he gives the system a thorough checking-over. I'd try to get a written note of his name, company, and findings so if you want to reclaim the cost of the wasted water and/or gas from the landlord you have the evidence needed to do so.

 

[John.g]

Well really all the showers etc. mixer taps should of been taken off the Balance cold on the Combination Valve on the cylinder to prevent this. The easiest way to sort this would be either fit a PRV on the incoming main to 3 bar, or fit a Non return valve to the Hot Outlet on the cylinder.

Apparently there is a PRV installed on the mains after the stopcock with a PG after it, the plumber found the PRV full open with a apparent mains pressure of 6.0/6.5bar but its a bit strange that this faulty shower was causing the pressure to fall to 4.5bar with it fully open, he has now reduced the PRV pressure to 3.5bar, if this pressure falls excessively with water usage then possibe PRV fault or stopcock or mains restriction that was the reason for the PRV wide opening in the first place and the installation of a pressure gauge?.

 

[John.g]

No I hadn't noticed anything about the heat up times. This is the first time we have had this system and the first we knew about a problem was when the water company commented that we are using very large amounts of water.

Is the water consumption normal now?

 

[JX350C]

Apologies for the radio silence for a while. I've been busy at work and had to work all weekend.

I've been busy taking meter readings most days and especially keeping an eye on overnight readings when we were losing the largest volumes of water. I wanted to ensure that the readings actually reflect our usage so I have been logging each use and then comparing them to the meter reading usage. So far the usage matches the meter readings so this does look like this problem is now fixed. I am continuing to take readings just to ensure they are all good. If all is now good the landlord said he will get the shower fixed as well. He has at least now listened to the evidence and the plumbers findings so has agreed that the problem is not the meter at fault.

Thanks for all the help with getting to the bottom of this. It was very frustrating trying to prove the usage was not from our use but the last plumber was great and saw for himself the constant water usage. It was such a relief when he found the cause of the problems.

Question now is, who should pay me back for all the water that was used that was not our fault.

 

[Chuck]

Question now is, who should pay me back for all the water that was used that was not our fault.

Consult your household insurance, but I'm pretty sure my policy wouldn't cover your scenario. I think that the landlord is the only person you have a claim against. (They, in turn, might be able to pursue the builder of the house.) Seek advice from a solicitor or Citizen's advice before making a claim.

Your landlord will probably assert that they are only responsible for the losses that occurred after you notified them of the problem, which is a position I have some sympathy for but which may or may not be how the law would see it.

It may be worth seeing if the water supplier will give you a rebate. I think this would be discretionary on their part but given the efforts you had to go to identify and fix the leak they might play ball.

Citizens Advice is a charitable organisation. If you consult them and can afford to make a donation, please do so.

 

[Enthalpy]

I would ask the water company to consider a lost water allowance

You could thank the water company for bringing the high water usage to your attention. Explain what has been done to resolve the problem. It might help to inform the water company that you are a tenant.

Good luck.

 

[John.g]

This was a new build so possibly not installed correctly as the cold water supply to the HW cylinder was/is not from the balanced cold connection on the combination valve set, and the HW expansion valve may not have been set correctly to 6.0 bar or it was reduced to 3.5/4.0 bar, it certainly looks as if it wasn't commissioned properly, if at all, the mains PRV was fully opened with the stopcock left throttled in.

 

[JX350C]

This was a new build so possibly not installed correctly as the cold water supply to the HW cylinder was/is not from the balanced cold connection on the combination valve set, and the HW expansion valve may not have been set correctly to 6.0 bar or it was reduced to 3.5/4.0 bar, it certainly looks as if it wasn't commissioned properly, if at all, the mains PRV was fully opened with the stopcock left throttled in.

Yes I totally agree. I'm convinced this has been a problem since we moved in. We have written to the water company to see what they say.