Poor flow - first thing to check?

[alexp.1]

Cold water flow rate has deteriorated in my house to about 6 litres per minute. Water company have checked at the meter and they are providing a respectable 25 litres per minute at 4 bar.

What's the first thing I should check in my house? I was thinking of replacing the stopcock in case it has seized...

I have a 9 year old sealed system with a Megaflo. Showers aren't fun any more.

 

[dextrous]

stopcock would be the first logical place.

 

[gas4you]

Or the filter in the multifunction valve next to the megaflo in the cold supply to it.

 

[bengasman]

Incoming mains in lead, copper or plastic, and what size?

 

[alexp.1]

Incoming mains in lead, copper or plastic, and what size?

Can't be sure but the incoming pipework that I can see emerging from the ground is 32mm blue plastic pipework which then connects to a 22mm stopcock.

I live on a modern development about 9 years old.

 

[bengasman]

If you can see blue plastic in a new house, it is fair to assume it is the same all the way back to the meter.
Plastic stopcocks don't seize a lot afaik.
Is the flow poor on each and every tap, hot and cold alike?

 

[alexp.1]

The stopcock is metal.

Flow is equally poor from all cold taps but much better from the hot taps (which is odd because I always thought the hot output from a Megaflo was at the same rate as the incoming cold feed?)

Just downstream from the stopcock is a pressure reducing valve closely followed by a pressure relief valve.

Here's a pic;

 

[simond]

I would start by checking that your Megaflo is not discharging water down the tundish.

Then I would check the strainer in the Combi Valve.

 

[alexp.1]

I would start by checking that your Megaflo is not discharging water down the tundish.

Then I would check the strainer in the Combi Valve.

Thanks.

Tundish is bone dry (and I regenerated air gap a few weeks ago).

Why would a blocked strainer into the Megaflo cause flow problems to all the cold water taps in the house?

 

[holty]

Why would a blocked strainer into the Megaflo cause flow problems to all the cold water taps in the house?

usually the cold feeds are balanced off the combinaton valve wich looks like it is on your pic. have to say i love the fact that the expansion relief valve is capped off.

 

[holty]

oh and the drain off is near useless.

 

[gas4you]

All I can say is what a mess

I always put the combination valve next to the megaflo

 

[holty]

wow just managed to find a pipe clip and a screw head that acts as one. quality.

 

[bengasman]

32mm plastic coming in,with brass stopcock; that is really clever.
Could well be that your stopcock is the culprit.

 

[holty]

were the hell did you get 15mm stoptap from it clearly says 22 on it.not right this time.