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

[SimonG]

:leaving:

 

[LCV]

This posting started off with the question whether 3+minutes was normal to get hot water in the kitchen. I thought it could be to do with a setting on the boiler. I did not even connect it to the circulating ring because that, in my mind, was in relation to getting hot water in the loft so why would my kitchen be affected.

 

[ShaunCorbs]

This posting started off with the question whether 3+minutes was normal to get hot water in the kitchen. I thought it could be to do with a setting on the boiler. I did not even connect it to the circulating ring because that, in my mind, was in relation to getting hot water in the loft so why would my kitchen be affected.

the longer the run the more cold water you have to draw off before fresh hot water from the cylinder is used, the pipe might not be lagged/ insulated

with a secondary return the cold water in the pipe is sent back to the cylinder and fresh hot water is put in its place

in simple terms

 

[LCV]

Thanks for explaining Shaun.

What I can't get my head round is why it takes such a long time to get hot water in the kitchen. I know the boiler has been moved from the kitchen to the Utility room but when the boiler was in the kitchen I didn't have to wait over 3 minutes to get hot water in the Utility room. The wait was more like 40seconds. My husband thinks the hot water must go to the loft first before coming back down to the kitchen in order to take that long rather than straight from the Utility room to the kitchen...

Hopefully it will all be resolved and this will be a story I will tell to my children when they are older about the dramas involved with renovation projects.

 

[ShaunCorbs]

Thanks for explaining Shaun.

What I can't get my head round is why it takes such a long time to get hot water in the kitchen. I know the boiler has been moved from the kitchen to the Utility room but when the boiler was in the kitchen I didn't have to wait over 3 minutes to get hot water in the Utility room. The wait was more like 40seconds. My husband thinks the hot water must go to the loft first before coming back down to the kitchen in order to take that long rather than straight from the Utility room to the kitchen...

Hopefully it will all be resolved and this will be a story I will tell to my children when they are older about the dramas involved with renovation projects.

from the boiler to the kitchen distance wise? and very unlikely it will go upstairs first and then back down to the kitchen

 

[LCV]

It is around 8 meters away, is that big? The kitchen and living room is open plan so one room. The Utility room is next to the living room, so across the living room to get to the kitchen sink.

 

[ShaunCorbs]

It is around 8 meters away, is that big? The kitchen and living room is open plan so one room. The Utility room is next to the living room, so across the living room to get to the kitchen sink.

depending on run you could have 10-12m maybe 15m if theres things in the way of pipework esp if its un- insulated yes

at a rough guess 0.2L per m of 15mm or 0.35L for 22mm

worst case 22mm estimated at 15m 5.25L

 

[LCV]

Sorry this doesn't mean anything to me. How does this translate timewise? Are you saying 3+mins is normal then because of the distance? If so, why didn't I have an issue with the time to hot water in the Utility room when the boiler was in the kitchen?

 

[ShaunCorbs]

Sorry this doesn't mean anything to me. How does this translate timewise? Are you saying 3+mins is normal then because of the distance? If so, why didn't I have an issue with the time to hot water in the Utility room when the boiler was in the kitchen?

depends on factors length and run of pipework is it insulated etc, but building reg/water regs state you must have hot water within 30 seconds

"government guidance recommends that when opening a hot water tap, or other outlet, the water should reach 50°C within 30 seconds." to stop wastage of water

 

[LCV]

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.

 

[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?