Combi water flow too high?

[new_DIYer]

Hello,

Just had a new kitchen and the installer replaced and worked on the water supply into the house. This resulted in a new stopcock.

I live in a fairly big house and prior to the work the water flow was "acceptable" but not the best I had seen. The boiler delivered consistent hot water even with taps on full flow.

Since the work, the water flow is so much better and the showers run perfect. However, the combi boiler seems unable to keep up with the flow (Glow Worm Ultracom 38CXI). In the showers it runs hot for a few seconds burst then tails off before warming again. The kitchen sink tap also does the same.

Am I better off reducing the flow at the main stopcock in the street, the stop cock in my house or reaching the flow into my boiler? A crude test of flow shows it takes 7 seconds to fill 1L from the cold tap closest to the stop cock.

All or any advice much appreciated.

 

[ianmcd]

cold tap has nothing to do with it, you need to measure the flow rate at the hot taps, the flow rate for the HW is set at the boiler , nothing to do with the stop cock

 

[new_DIYer]

Hot water flow is 60 L / min

Boiler has not been touched at all, only stop cock changed.

 

[lightning]

Think you need to measure that again

 

[AGAS]

Am I better off reducing the flow at the main stopcock in the street, the stop cock in my house or reaching the flow into my boiler?

why didn't you try reducing the stop cock before asking here as it would have been quicker , as you seem to know about temperature rise

 

[new_DIYer]

Sorry, forgot to check the auto correct before submitting. Correct figure is 10L.

@AGAS - I asked which stop cock if you read my question. It was a simple question and didn't warrant sarcasm.

 

[Agile]

As you have been advised any hot water flow setting is done at the boiler!

However, you boiler can heat about 12 litres per minute so will not need any flow rate reducing if it is only 10 li/min.

If the boiler is cycling hot/cold then it would imply a boiler fault. It could be that the now increased flow rate has just showed up the fault.

This is often caused by a blocked plate heat exchanger. Do you ever have your boiler serviced?

Tony

 

[new_DIYer]

Yes, boiler is serviced regularly. Was serviced June 2016 and March this year.

The burner does come on but then goes off before repeating the cycle. Both service guys have commented it was difficult to get an emission reading but said they have seen this type of action on these boilers previously.

 

[AGAS]

Both service guys have commented it was difficult to get an emission reading but said they have seen this type of action on these boilers previously.

their probably talking shyte they are probably using the hot water to get an fga reading which isn't the proper way , but on the system boiler type he's right

was that sarcasm alright