DHW has no pressure

[Moorf]

It's a Glow Worm Betacom 24c condensing combi and as the title says it has no pressure in the DHW to the point that the thermostatic shower dosn't work any more.

The heating works fine and the cold water pressure is fine. The boiler is about 4 years old, was serviced and tested in June and I've checked the little filter on the cold water feed into the boiler, which is clear.

Any ideas appreciated. Many Thanks!

 

[PrenticeBoyofDerry]

Do you have any hot water at the taps?

 

[Moorf]

Yes, but there's very little pressure.

 

[Stadan20]

More than likely to be the plate hex

 

[jeff the gasman]

I've been in places where shower valve and taps were knackered. No problem with boiler but boiler got the blame.

 

[Moorf]

There's no pressure at any of the hot water taps in the kitchen or bathroom.

What's the plate hex?

 

[PrenticeBoyofDerry]

Hex Plate would require gas safe engineer.

It would be possible to check hot water pressure/flow rate at the boiler outlet. But would require isolation of water and removing DHW outlet pipe. You could manufacture connection to a hose pipe to check this, with water back on.
This could rule out or in the boiler.

 

[jeff the gasman]

There's no pressure at any of the hot water taps in the kitchen or bathroom.

What's the plate hex?

The plate heat exchanger is a water to water cross flow heat exchanger. It looks like a stainless steel box with ridges which are the water ways.
Some older combis had a calorifier instead.

 

[PrenticeBoyofDerry]

Does the boiler display any fault codes?

 

[Moorf]

Ah yes the heat exchanger. I did wonder if that has become clogged or scaled up and yes I know that'll have to be a job for the Gas Safe guy, but forewarned is forearmed and all that!

If it is the heat exchanger clogged up, what's the solution? New heat exchanger? or can they be cleaned out? I had a heat exchanger go in a another place a few years ago on a 6 year old Ferroli combi and it worked out cheaper to replace the boiler, which was pants!

There's no fault codes on the boiler.

 

[picasso]

Take the strainer off one of your taps and see if the pressure /flow improves.

 

[Stadan20]

Personally I would recommend a replacement hw hex . I haven't even attempted to de scale one before as to me its more hassle

 

[picasso]

Do you live in a hard water area ?

 

[Moorf]

Not especially. The boiler that this one replaced was a 20 year old Worcester combi which went on and on with no problems, until it eventually died from a leaking heat exchanger. I think modern boilers are crap!

I'll try taking the strainers off the taps to see if that makes a difference. Thanks!

 

[gigz]

You haven't turned the cold inlet down at the boiler by any chance have you ? First place i would check.