Worcester Greenstar 25Si DHW problem

When I checked and noticed the low flow rate, I closed the stopcock and repoened it fully. No change.

Literally this is how it is.

[code:1]
Outside Tap (2.25bar 22ltr/min) Kitchen Tap (6ltr/min) Boiler (1.5bar 6ltr/min)
| | | |
| | | |
| 1mtr | 1mtr 1mtr | |
_______|_____________________________|______________________________| |
| | |
| | |
| Stopcock Rest of house (Hot)
Rest of house (Cold) |
|
Cold Water Supply
[/code:1]

I will do "rest of house" tests tonight for ltr/min (unfortunately I don't have a pressure meter so I cannot test the pressures.
 
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Does the kitchen tap have a flow restrictor maybe? Doesn't make sense for it to be better AFTER the kitchen tap! :unsure:
 
That's what I thought. When I get in I'm going to start kicking things and doing my own diagnosis. Something VERY fishy going on.

Will let you all know (for future fault finders).
 
OK, so all tests done by myself including taking the taps apart.

It seems that in the kitchen tap, there's a stupid eco-flowreducer!

Kitchen tap problem identified.

Moving on to the boiler, I'm going to have to get an engineer out to flush it I think. The Thames Water guy suggested that it should be done every 2 years at my location! AGH!
 
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I am guessing that you have measured the static pressure and the open pipe flow rate.

In that case can you explain why you have static pressures differing at the various places?

Tony
 
The pressure at the boiler was a reading from the boiler pressure guage as Thames Water guy (quite rightly) will not test pressure there.

The other places he tested pressure seemed consistent at 2.25bar.

Flow rates are 22ltr/min on outside tap (the only other tap on the ground floor apart from the kitchen tap) and 18ltr/min upstairs.

So it seems the kitchen tap was throwing a red herring with the flow rates. Now I'm convinced the boiler is about ready to go in the bin. Far too many repairs to keep it.

I'm giving it one last chance with a system flush, I cannot afford to throw good money after bad.

No-one can seem to give a definitive "It's Y" or "It's Y", even the 4 engineers we've had in before who ripped it apart and replaced parts like nobodies business (I'm glad I wasn't paying for each part then as that would've cost more than the boiler).
 
Hmmmmmm! The boiler has a flow restrict or in it also. When you run the hot on its own is it ok? Does it only go off when you start to mix it with cold?
 
No, it doesn't matter whether hot only or both, it seems to do it more when the c/h is actually running.

Incidentally, I've noticed that whilst running the hot tap for a while a click is heard, the "pilot light" goes out, the hot water turns cold, then about 20 seconds later, another click and the light comes on and the hot resumes.

SO frustrating.

Also, the pressure gauge shows the pressure dropping every night (from whatever I set it to 1bar-1.5bar) to almost 0bar. I refill it every morning before I have a shower.

This pressure is NOT released in the piping system as I have no leaks that I can identify. I did notice that one of the output pipes (one of the two that expel excess/pressurised water) is being used a lot and I think that is where the pressure/water is going.
 
Ok so sounds like a few things going on now. If the PRV is opening then by first guess is that at the very least it needs draining down (the boiler) and the expansion vessel recharged/replaced. The hw clicking on and off can be for various reasons but all of them require an engineer. If I were you I would put it on a Worcester plan they will fix it regardless of cost/parts. The issues you have, from the sounds of it, would exceed a yearly premium to fix so it's a win win for you. Either way this is not something you can rectify as a DIY job.
 

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