Glow Worm 30 CXI. Hot Water Running Hot And Cold

[TheOP]

Hello all.

My brilliant high quality Glow Worm combi is playing up again.

This time, the hot water is running hot, then going cold, then back to hot again after a min or two.

Any suggestions of where I should start looking, as cold showers loose their appeal in October.

 

[lightning]

Blocked plate . Full of scale

 

[TheOP]

Thanks for quick reply.

Is that limescale? Bristol has hard water. I'm a bit surprised as I have a Cistermiser combimate.

Or is it dirt from system? Can HE be cleaned or is it replacement time? I have done a couple of jobs on this boiler, is the plare HE DIYable? If yes, any advice appreciated.

 

[TheOP]

ALSO - When hw is going hot and cold, the tops of the rads get warm. Is this also a scaled plate HE?

Thanks

 

[TheOP]

BUMP.

Me again.

 

[45yearsagasman]

No, when that occurs its a diverter valve passing. I would also clean the primary side of the plate. Probably not scaled but system debris.

 

[mickyg]

watch the boiler display while your running the tap, it may intermittently flash "F14". This is an indication of a blocked plate, as is the diverter passing. Don't replace the diverter at this point unless your happy to replace as a precaution, as they tend to get forced open with the back pressure of the blocked plate he, and once clean or replaced normal operation should resume. Its amazing how badly these things will block before indicating a fault, this one below was removed from the same boiler as you have , look at the top right port in the picture, its overflowing with cr*p.

Untitled

• mickyg
• 26 Feb 2009
• 12

 

[TheOP]

Thanks Mickyg. Yes, I have seen F14 once over the last few days in this ongoing saga. F5 and a lock-out seems to feature more though.

Getting other 'interesting' symptoms too. Eg.

1) Today, arrived home, 3/4 filled kitchen sink with hot water, turned off hot tap, and radiator behind me started heating up a bit. Boiler also locked out on F5. Water was schorching hot.

2) Later, after resetting 0/h stat in boiler, turned on hot tap. Water was luke warm. Went to boiler, and turned hw control down from high to medium. Burner started roaring away, and water was scorching hot again. Why did burner start running furiously and water get hotter when I had turned the control down??????

This boiler is a nightmare.

Heating works perfectly though!

 

[Rob]

This boiler is a nightmare.

Not the boilers fault the system it's connected to is full of **** and as mickyg says the cxi copes quite well with it.

 

[Agile]

This is all because your super cheap installer did a super minimum job and never power flushed the system or added any cleanser or inhibitor!

Cheap job means a poor quality job!

 

[simond]

Might not have been cheap but if you've got a blocked secondary HEX it definitely isn't Gloworm's fault.

Not that I rate their stuff, but the best boilers will suffer in the same way if you fill them full of cack from the radiators.

Your installer probably got home in time for Jeremy Kyle; as a result you will need a new boiler soon. The mess will be all over the insides and cause ongoing aggro.

Powerflushing is boring, dull, and takes time to do properly. This is a lesson for the MoneySaving Experts; it's only cheap if it's done properly.

 

[Agile]

Its some time since I did a stand alone power flush for anyone!

I like to have an assistant otherwise I find that they are very good exercise if on my own.

I usually quote about £350 for a two bed flat or three bed house. Evidently doing the job properly with leading brand chemicals is obviously too expensive for those who just want the cheapest job.

Please tell me why I should continue to only quote to do the job properly using the best chemicals?

Surely I should be quoting £299 and doing it all in three hours using Unknown 800 to flush and Unknown 100 as the inhbitor?

Tony