Modena 80e - Low hot water pressure

[Bazboy]

Hi Peeps,

Wondering if anyone had seen this prob before.

Recently moved into a new house, mains pressure is superb but the hot water from the Combi runs out very slowly - measured at 3.2 litres/min on fully opened tap, this is the same if tried in the kitchen or bathroom.

Is there any adjustable valves to increase the hot water pressure? seems a tad low to me.....

Thanks in advance

 

[Rob]

The flow meter incorporates a filter and flow restrictor. Id start with removing or cleaning these.

Rob

 

[Bazboy]

Great, i'll give this a try.

Is there any parts to be wary of when dismantling the flow meter?

Cheers

 

[kevindgas]

quite simple this

its scaled up without a doubt the heat exchanger is dual pipe and the water side tubes are 10mm at best.
I descale these boilers regularly an absolute doddle to do and customer gets a bill for £88 as it usually takes about 1.5 hours to do properly.

 

[Bazboy]

Oh!

One thing i failed to mention, the pressure is higher for a split second on turn on of tap but it quickly reduces to the slower rate.

Cheers.

 

[kevindgas]

yes still my diagnosis is above
pressure will build in the pipework both sides of the boiler hence the spurt of faster water.

 

[Bazboy]

Ah, Thanks Again.

How would i go about descaling? Do you have a good way of doing it?


Cheers

 

[Gasguru]

The flow meter incorporates a filter and flow restrictor. Id start with removing or cleaning these.

Rob

Check the cold inlet valve is fully open (take off the plastic lever and check..the lever can split), then check the above (remove the O ring in the flow limiter if necessary). AFAIR the limiter is in the flow turbine inlet. Only after these checks (cost of washers only) assume scaling.

Initial higher flowrate may just be due to a dead leg ie. redundant pipework containing trapped air (acts as a spring).