Over 3 mins to get hot water in kitchen - is this normal?

[ShaunCorbs]

Do you know which section of building regs your quote came from so that I can refer to it. It does say it is only a recommendation though.

I had instructed private building control for my renovation project but the surveyor for some reason is not replying to my e-mails about this issue as I had asked him first whether 3+mins was normal before posting here.

3.7 g3

"Pipework should be designed and installed in such a way as to minimise the transfer time between the hot water storage system and hot water outlets."

also

4.4.1

"In small systems, with normal tap running times and a maximum delay of 30 seconds for the hot water to reach the outlet, the pipes would be subjected to sufficient temperature to kill Legionella (or inhibit growth) without the need of secondary circulation."

but something is wrong

 

[LCV]

Thank you Shaun. I presume my house despite being on 4 floors is still classified as a small system.

 

[ShaunCorbs]

Thank you Shaun. I presume my house despite being on 4 floors is still classified as a small system.

yes was from my commercial book

could you measure how much water is drawn off before it becomes hot please?

 

[ShaunCorbs]

if my math is right a bristan kitchen/ any tap has a flow rate of about 10-15 lpm (estimated)

so take it at 10 and you dont have hot water for about 3 mins

thats 30L does that sound about right (ballpark)

 

[LCV]

I can fill my kitchen sink to the top before it gets hot. Would the measurement of my sink be sufficient?

 

[ShaunCorbs]

I can fill my kitchen sink to the top before it gets hot. Would the measurement of my sink be sufficient?

need to know how many l your sink holds you could try with 1 or 2 L bottle of pop and see how many it takes before you get hot water

 

[LCV]

Do you feel like there is something else wrong aside from not having the secondary return? I don't know why but something is not sitting right with the length of time the taps in my house is taking. My neighbour across the road lives in a very similar house but his combi boiler is located on the 3rd floor and he doesn't have to wait minutes to get hot water to his kitchen.

Actually, just thinking about this a bit more. I have another neighbour who lives in an identical house (these are new houses 11 years old on a new street so all the houses are built the same size and layout). He had a loft conversion but did not change his combi boiler. I am going to ask him to time how long it takes to get hot water in his loft.

 

[LCV]

Ah okay. I will do that tomorrow and post back. Thanks you so much and goodnight.

 

[ShaunCorbs]

Do you feel like there is something else wrong aside from not having the secondary return? I don't know why but something is not sitting right with the length of time the taps in my house is taking. My neighbour across the road lives in a very similar house but his combi boiler is located on the 3rd floor and he doesn't have to wait minutes to get hot water to his kitchen.

Actually, just thinking about this a bit more. I have another neighbour who lives in an identical house (these are new houses 11 years old on a new street so all the houses are built the same size and layout). He had a loft conversion but did not change his combi boiler. I am going to ask him to time how long it takes to get hot water in his loft.

like i have said before factors on a few things like pipe runs/ length, is it insulated, dia of pipe work etc

tbh i would of put a secondary return in anyway as while your doing the lot its one extra pipe that can matter

and good night

 

[LCV]

Oh okay. I understand. It is difficult to make a real assessment without all the relevant information.

 

[gastec]

What size is the incoming water mains?

 

[LCV]

Hi Shaun - test done at 3:40pm. Time taken to get hot water is 2mins 40 seconds. 10.8 litres.
Does the time of day make a difference? Also, I had to stop and start as I only have one empty 2L plastic bottle, i.e. once the bottle was full I turned off the tap, emptied the bottle and refilled. Do not know if this affects the results in anyway.

 

[LCV]

Hi Gastec - sorry I don't know and I wouldn't be sure of which pipe to measure.

The house is 11 years old. Your question has made me think whether the location of the water mains could be causing the time lag. I think my mains water pipe is at the front of the house. The Utility room where the boiler and cylinder is located is at the back of the house.

 

[Riley]

Hi Shaun - test done at 3:40pm. Time taken to get hot water is 2mins 40 seconds. 10.8 litres.
Does the time of day make a difference? Also, I had to stop and start as I only have one empty 2L plastic bottle, i.e. once the bottle was full I turned off the tap, emptied the bottle and refilled. Do not know if this affects the results in anyway.

those results sound ridiculous that's under 5 L a minute. My naff gravity hot water at home will do 10 L a minute easily. It sounds to me like you have a bigger problem there Also stopping in between each 2 L is going to make a mess of the results. maybe get a couple of 5 L buckets from the hardware store

 

[Riley]

Hi Gastec - sorry I don't know and I wouldn't be sure of which pipe to measure.

The house is 11 years old. Your question has made me think whether the location of the water mains could be causing the time lag. I think my mains water pipe is at the front of the house. The Utility room where the boiler and cylinder is located is at the back of the house.

Why do you think it's causing an issue ?? Were you given the option to upgrade your mains if necessary The correct operation of an unvented cylinder is very dependent on the flow and pressure of water. Do you know where your stopcock is if so take a photo of it to include the pipe entering and exiting it

 

[LCV]

if my math is right a bristan kitchen/ any tap has a flow rate of about 10-15 lpm (estimated)

so take it at 10 and you dont have hot water for about 3 mins

thats 30L does that sound about right (ballpark)

Just rereading this comment. Wow, 30L, that is a lot. I thought filling over five 2L bottles before I got hot water was bad but okay my situation is not as bad as this. When I wash up I don't turn on the tap at full blast otherwise the water would spray everywhere. Generally I turn on the tap, wait for the water to become hot and when it is hot I increase the flow. In the test I had it a bit higher than medium flow.

 

[ShaunCorbs]

those results sound ridiculous that's under 5 L a minute. My naff gravity hot water at home will do 10 L a minute easily. It sounds to me like you have a bigger problem there Also stopping in between each 2 L is going to make a mess of the results. maybe get a couple of 5 L buckets from the hardware store

Won't harm that much tbh will give you a rough Idea
And agree somewhere there is a problem, maybe a half closed valve or rubbish in a strainer etc

Would need a G3 eng to check those tbh

 

[rpm]

Oh okay. I understand. It is difficult to make a real assessment without all the relevant information.

More like impossible I`d say !

 

[LCV]

those results sound ridiculous that's under 5 L a minute. My naff gravity hot water at home will do 10 L a minute easily. It sounds to me like you have a bigger problem there Also stopping in between each 2 L is going to make a mess of the results. maybe get a couple of 5 L buckets from the hardware store

Hi Riley - I see, shall I redo the test but turn on the water at full blast? I need to get the bucket first.

 

[Riley]

I think the simple answer here is LCV needs to get another engineer in to take a look there is a number of things here that don't add up and over the Internet it's Nigh on impossible for us to work out with a massive degree of accuracy

 

[Riley]

Hi Riley - I see, shall I redo the test but turn on the water at full blast? I need to get the bucket first.

How open did you have the taps?

 

[LCV]

Why do you think it's causing an issue ?? Were you given the option to upgrade your mains if necessary The correct operation of an unvented cylinder is very dependent on the flow and pressure of water. Do you know where your stopcock is if so take a photo of it to include the pipe entering and exiting it

I thought perhaps the delay could be caused by cold water having to travel from the mains to the boiler and then back to the kitchen. Whereas when the boiler was in the kitchen it was pretty close to the mains.

 

[LCV]

Over half way. I have a Franke swan tape with a water filter.

 

[LCV]

Sorry I don't know what a stopcock looks like. I need to google this. Is it normally under the sink or by the cylinder?

 

[Riley]

You no longer have a Combi boiler you now have a store of hot water in the hot water cylinder. Which is heated by your boiler. For the kids during the day as you use hot water obviously this is replaced by cold water going into the cylinder Depending on your heating/ Hot water settings The boiler will sporadically turn on and bring the water in the cylinder back up to temperature during the day. With the greatest of respect it doesn't sound like you've had your system explained to you as you don't understand how the system components work which other

 

[Riley]

Over half way. I have a Franke swan tape with a water filter.

Are you pulling through just hot water or a mix of hot and cold

 

[Riley]

Sorry I don't know what a stopcock looks like. I need to google this. Is it normally under the sink or by the cylinder?

You really really really need to speak to the builder/plumber and have these things explained to you. What are you supposed to do in the event of an emergency and you need to turn the water off. If as you say the mains water enters your property through the front of the house it is likely that there will be a brass tap or a lever valve. If you know where the mains enters the property then it should be there

 

[Riley]

 

[LCV]

It is embarrassing how little I know. TBH I would prefer my husband dealt with this but he is worse than me.
The plumber used by the builder doesn't speak great English so we don't really understand what he is saying.
Here is a picture of the cupboard under my sink. I can't see anything that looks like that image you sent Riley. I need to open the panel which houses the sprinkler maybe it is in there. We had to have a water sprinkler fitted to meet building regs.

 

[Riley]

I'm sorry but that doesn't show us anything. A photo near the hot water cylinder might show it

 

[ShaunCorbs]

must be one bloody big house to have a sprinkler system fitted you sure you dont mean fire alarms?

 

[ShaunCorbs]

I'm sorry but that doesn't show us anything. A photo near the hot water cylinder might show it

post 23 mate

 

[LCV]

Are you pulling through just hot water or a mix of hot and cold

Just turned the hot handle.

 

[LCV]

must be one bloody big house to have a sprinkler system fitted you sure you dont mean fire alarms?

Unfortunately, for us, a recent change in building regs means that if a house is over 4+ floors they must fit a sprinkler system.

 

[ShaunCorbs]

Unfortunately, for us, a recent change in building regs means that if a house is over 4+ floors they must fit a sprinkler system.

bet that cost you a bit