Omega Owners Forum

Chat Area => General Discussion Area => Topic started by: llewellyn237 on 30 October 2012, 21:51:02

Title: Anyone know much about combi boilers?
Post by: llewellyn237 on 30 October 2012, 21:51:02
Need to release some pressure for a start.

Also, the hot water from kitchen tap is near scalding yet I can easily hold my hand under the bath hot tap all day :-\

Thought I'd try here first rather than plough through a Google search...
Title: Re: Anyone know much about combi boilers?
Post by: Steve B on 30 October 2012, 21:56:38
have you got bleed off valves under your ground floor rads  radiators  ;D ;D
Title: Re: Anyone know much about combi boilers?
Post by: llewellyn237 on 31 October 2012, 08:45:11
Yeah but water comes straight out, no air  :-\
Title: Re: Anyone know much about combi boilers?
Post by: martin42 on 31 October 2012, 19:46:33
drain the water out the bleed valve on rad,but do it with heating off,it should be between 1 and 1.5 bar,there should be a temp switch for hot water,where the clock and rad temp is :y
Title: Re: Anyone know much about combi boilers?
Post by: llewellyn237 on 31 October 2012, 21:14:56
Nice one, drained some water out and pressure has dropped  :y

Bath hot tap is still considerably cooler than kitchen one though  :-\ (water temp gauge is maxed)
Title: Re: Anyone know much about combi boilers?
Post by: Shackeng on 31 October 2012, 22:45:18
I use this forum for info on many things, but certainly you will get help on boilers. DIYnot.com

HTH :y
Title: Re: Anyone know much about combi boilers?
Post by: martin42 on 31 October 2012, 22:49:13
Nice one, drained some water out and pressure has dropped  :y

Bath hot tap is still considerably cooler than kitchen one though  :-\ (water temp gauge is maxed)
When you turn hot tap on,don't have it open fully,only half way,then it will be hotter,but will take longer to fill a bath :y
Title: Re: Anyone know much about combi boilers?
Post by: llewellyn237 on 31 October 2012, 23:43:27
I use this forum for info on many things, but certainly you will get help on boilers. DIYnot.com

HTH :y
:y cheers!
Nice one, drained some water out and pressure has dropped  :y

Bath hot tap is still considerably cooler than kitchen one though  :-\ (water temp gauge is maxed)
When you turn hot tap on,don't have it open fully,only half way,then it will be hotter,but will take longer to fill a bath :y
Really? Simple as that? Cheers bud!
Title: Re: Anyone know much about combi boilers?
Post by: Marks DTM Calib on 01 November 2012, 08:07:22
Agreed, flow dependent  would say.

Your averga kitchen tap has a smaller feed and bore, this restricts the flow and hence the temp goes up. Bath taps on the other hand are a larger bore and hence flow more.

As for DIY.COM , its fine if you want half the UK's plumbers saying 'call a plumber', 'dont touch gas' etc  ;D ;D
Title: Re: Anyone know much about combi boilers?
Post by: llewellyn237 on 01 November 2012, 09:48:36
Simple when you know how eh!!?

Cheers lads, appreciated.
Title: Re: Anyone know much about combi boilers?
Post by: omega3000 on 01 November 2012, 10:25:30
Nice one, drained some water out and pressure has dropped  :y

Bath hot tap is still considerably cooler than kitchen one though  :-\ (water temp gauge is maxed)
When you turn hot tap on,don't have it open fully,only half way,then it will be hotter,but will take longer to fill a bath :y

Our bath is like that , it takes ages to fill on half open tap . What i cant understand is the boiler is still heating the water but when the tap is open full it comes out cold  :-\
Title: Re: Anyone know much about combi boilers?
Post by: llewellyn237 on 01 November 2012, 10:47:28
I'm guessing the boiler doesn't have time to heat the water when the tap is fully open?  :-\

Boilers are one of those things I wish I knew more about. My knowledge on them is zero  :-[
Title: Re: Anyone know much about combi boilers?
Post by: Kevin Wood on 01 November 2012, 11:24:36
The boiler has a limited maximum heat output therefore the temperature rise of the water flowing through it depends on the flow rate of the water. If the water flows fast the boiler will only increase its' temperature by a few degrees. If it flows slowly it will increase it more significantly.

Also, bear in mind that combo boilers also often have a small volume of water retained at a high temperature to reduce the delay, so when filling a sink this comes into play. You won't notice the limited heat output until filling something more capacious like a bath.

Also, ask yourself why you needed to reduce pressure in the system? It it was previously over-filled then fine. If the pressure is increasing on its' own then it indicates a leak through either the filling loop or from the secondary to the primary side of the combi heat exchanger.
Title: Re: Anyone know much about combi boilers?
Post by: cem_devecioglu on 01 November 2012, 11:31:24
Agreed, flow dependent  would say.

Your averga kitchen tap has a smaller feed and bore, this restricts the flow and hence the temp goes up. Bath taps on the other hand are a larger bore and hence flow more.

As for DIY.COM , its fine if you want half the UK's plumbers saying 'call a plumber', 'dont touch gas' etc  ;D ;D

 ;D ;D ;D :y
Title: Re: Anyone know much about combi boilers?
Post by: Kevin Wood on 01 November 2012, 11:34:08
Agreed, flow dependent  would say.

Your averga kitchen tap has a smaller feed and bore, this restricts the flow and hence the temp goes up. Bath taps on the other hand are a larger bore and hence flow more.

As for DIY.COM , its fine if you want half the UK's plumbers saying 'call a plumber', 'dont touch gas' etc  ;D ;D

 ;D ;D ;D :y

It's fun winding them up, though. ;D
Title: Re: Anyone know much about combi boilers?
Post by: omega3000 on 01 November 2012, 12:59:19
Well i can just about get in the bath but cant get back out so dont use it  ;D
Title: Re: Anyone know much about combi boilers?
Post by: llewellyn237 on 01 November 2012, 15:15:58
The boiler has a limited maximum heat output therefore the temperature rise of the water flowing through it depends on the flow rate of the water. If the water flows fast the boiler will only increase its' temperature by a few degrees. If it flows slowly it will increase it more significantly.

Also, bear in mind that combo boilers also often have a small volume of water retained at a high temperature to reduce the delay, so when filling a sink this comes into play. You won't notice the limited heat output until filling something more capacious like a bath.

Also, ask yourself why you needed to reduce pressure in the system? It it was previously over-filled then fine. If the pressure is increasing on its' own then it indicates a leak through either the filling loop or from the secondary to the primary side of the combi heat exchanger.

It's simple really, when you think about it. But still, one of those easy when you know things.
Title: Re: Anyone know much about combi boilers?
Post by: Shackeng on 01 November 2012, 18:58:03
Agreed, flow dependent  would say.

Your averga kitchen tap has a smaller feed and bore, this restricts the flow and hence the temp goes up. Bath taps on the other hand are a larger bore and hence flow more.

As for DIY.COM , its fine if you want half the UK's plumbers saying 'call a plumber', 'dont touch gas' etc  ;D ;D

I haven't tried them, but have had much help on Diynot.com over the past 10 years, in particular relating to boilers. :y