combi HW flow rates should restrictors be used to increase temps.

[cascas]

30kw combi is rated at around 12lpm of hot water. However this is honly for a 30deg rise. So if incoming is 10deg, outgoing is only slightly warm at 40deg.

If flow is reduced then water gets hot, the boiler then modulates to the temp selected (max 65deg happrox). Does anyone here use flow restrictors when fitting combi boilers. I am thinking that limiting the flow rate of say, bathroom basin, kitchen sink etc may be useful. - or just dont turn the tap as much?

 

[Anton]

Many boiler manufacturers recommend turning the tap down on the basin/bath etc to raise the temperature, some taps with brass internals will start to shut themselves off when the tap is turned down. Checking the gas rate would be the 1st thing to do, to ensure the gas supply is adequate.
Don't fit anything to a boiler unless it is supplied/approved by the manufacturer. Any required restrictor should already be fitted. Check the MIs.
If the installation is correct. Another way of controlling the flowrate is to fit a valve to the hot water outlet pipework below the boiler. I have done this in the past using a gate valve (which is quieter than a ball valve in operation) you can set the flowrate with this, and it enables you to turn any tap on fully with higher hot water temperature maintained. (use a flow rate measuring jug)

 

[SimonJohns]

You can get a device called a combimate. Never tried one but it is for this very problem

 

[AWheating]

the simple answer is the customer has the choice of adjuisting the flow rate at the tap to suit. flow restrictors can be problematic and lead to increased call backs. Ensuring the customer understands that turning down the taps flow will help increase temp should in most cases be adequate.

 

[Mike Jackson]

I've got flow restrictors on every outlet on my house. 10 l/min on the bath and shower and 8 l/min on everything else. This is more to ensure that no one outlet robs the entire flow and means that I can stand under the shower whilst SWMBO turns the hot tap on in the kitchen.

 

[Howsie]

40 degrees is plenty hot enough no?

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[dancinplumba]

I've got flow restrictors on every outlet on my house. 10 l/min on the bath and shower and 8 l/min on everything else. This is more to ensure that no one outlet robs the entire flow and means that I can stand under the shower whilst SWMBO turns the hot tap on in the kitchen.

like it mike
proper job. 🙂
have you used iso's ?

 

[cascas]

I've got flow restrictors on every outlet on my house. 10 l/min on the bath and shower and 8 l/min on everything else. This is more to ensure that no one outlet robs the entire flow and means that I can stand under the shower whilst SWMBO turns the hot tap on in the kitchen.

What restrictors are you using? Ballofix valves, or something like the arrow flow limiter? Arrow Valves Ltd - Automatic Flow Limiting Valves - Save water and energy

 

[Mike Jackson]

I'm using ball o fix valves with built in flow restrictions. I can't remember the make but they are available from BES.


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[dancinplumba]

sent from ipad using tapatalk HD mike....us oldies can do it, not me yet tho lol

 

[PlumbBobBob]

i think i know the ones you mean somebody had a link about them a while ago. are they the ones with different restrictors for different flow requirements that you can swap?

 

[Mike Jackson]

They're the ones. The flow restrictions are the same as the ones that you get with a lot of combos.


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[dancinplumba]

think they have diffrent colours

 

[Mike Jackson]

BES item number 17527 on page 105 of the online catalogue.

 

[doitmyself]

30kw combi is rated at around 12lpm of hot water. However this is honly for a 30deg rise. So if incoming is 10deg, outgoing is only slightly warm at 40deg.

I wouldn't call 40C "slightly warm". It's about the correct temperature for a shower.
These are the recommended maximum safe temperatures:

Shower 41°C; Washbasin 41°C; Bath 44°C

 

[AWheating]

BES item number 17527 on page 105 of the online catalogue.

you can get cheap flow restrictor inserts for taps but these are the one i would recommend. good quality and easy to maintain/change cartridge's.