What sort of mixer shower for combi-boiler

Joined
23 Feb 2007
Messages
538
Reaction score
0
Location
Hampshire
Country
United Kingdom
Well, I've had the combi-boiler fitted and now I want to put in a mixer shower over the bath. I like Grohe but I'm confused about what type to have. Is a manual valve a no-no? I had one of these before and it was wonderful but that was on a pumped system. All advice appreciated.
 
Sponsored Links
Joined
23 Feb 2007
Messages
21,178
Reaction score
1,936
Location
Norfolk
Country
United Kingdom
Whatever make you go for I would recommend a thermostatic model and make sure it is rated for combi use or mains pressure ;)
 
Joined
26 Jun 2004
Messages
64,092
Reaction score
4,620
Location
London
Country
United Kingdom
I would usually suggest a manual shower valve because the combis are limited to about 50 °C max so there is little risk of scalding and they are foolproof.

Some combis and some showers are virtually impossible to set properly although turning down the DHW temperature will usually help.

Tony
 
Joined
23 Feb 2007
Messages
538
Reaction score
0
Location
Hampshire
Country
United Kingdom
Agile said:
I would usually suggest a manual shower valve because the combis are limited to about 50 °C max so there is little risk of scalding and they are foolproof.

Some combis and some showers are virtually impossible to set properly although turning down the DHW temperature will usually help.

Tony
Thanks, Tony. When you say they might be difficult to set properly do you mean it's important to get the right combination? I have a Vaillant Ecotec Plus and the shower I really wanted (before I read that a thermostatic one was best) was a Grohe Avensys
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=67605
 
Joined
23 Feb 2007
Messages
21,178
Reaction score
1,936
Location
Norfolk
Country
United Kingdom
I always fit the Mira excel whenever I fit a shower to a combi, never had any problems. Even though you may only set the ecotec to 50-55C for hot waer it can still be a shock if somebody turns on a cold tap elsewhere momentarily :eek:
 
Joined
23 Feb 2007
Messages
538
Reaction score
0
Location
Hampshire
Country
United Kingdom
gas4you said:
it can still be a shock if somebody turns on a cold tap elsewhere momentarily :eek:

You've convinced me, Dave. I hate fluctuations in temperature. Thanks.
 
Joined
5 Jul 2006
Messages
1,242
Reaction score
42
Location
London
Country
United Kingdom
Also the Hans Grohe model has integral non return valves which play havoc with your flow rate I am always having customers asking if I can remove them especially from their Ibox system.
Pete
 
Sponsored Links
Joined
23 Feb 2007
Messages
538
Reaction score
0
Location
Hampshire
Country
United Kingdom
Thanks, Pete. I'm not sure what an Ibox system is, but it sounds like I should steer clear of Grohe. Pity. The Grohe Europlus in my old house worked wonderfully for 12 years - probably still going. But that was a pumped system.
 
Joined
26 Jun 2004
Messages
64,092
Reaction score
4,620
Location
London
Country
United Kingdom
All showers will either have integral non return valves or need them fitted on some installations to comply with water regs or just good practice. If the mains pressure is good they will not cause any significant problems.

Most modern combis will work with most modern thermo showers but the water pressure and pipe resistances will have an effect.

No shower can compensate for a DHW useage which exceeds the capability of the boiler.

The trouble is that there are too many variables and I find that a non thermo shower will never give any problem whereas a thermo might. I dont like to be blamed for any problems! In most cases problems are not predictable and are sometimes caused by unpredictable behavour by the occupiers.

Tony
 
Joined
20 Dec 2005
Messages
1,639
Reaction score
1
Location
Bedfordshire
Country
United Kingdom
Dont mean to hijack the post, but arnt Vailliant arranging free repairs on the ecoTEC plus & ecoTEC pro.

Just wondered if you knew about it? Had a letter from Vailiiant this morning requesting all installation addresses so they could send engineers in to do the repairs.

Heat exchanger seal degrading and leaving exposed plastic parts to suffer possible heat damage.

Dave
 
Joined
23 Feb 2007
Messages
21,178
Reaction score
1,936
Location
Norfolk
Country
United Kingdom
Yes thats right. They are sending out their group service engineers to replace seals with the new graphite ones. Very few failures though especially if they have been serviced regularly and range rated & co2 set correctly at commissioning. Saying that I had my first last Friday. Nothing much left of air pipe!! I fitted new seal foc and left it going for Vaillant engineer to check Sunday afternoon. In an extreme case the heat exchanger could warp as well and need replacing.

new seals are supposed to last for 5 years if undisturbed :rolleyes:
 
Joined
26 Jun 2004
Messages
64,092
Reaction score
4,620
Location
London
Country
United Kingdom
"""new seals are supposed to last for 5 years if undisturbed"""

Do you know what the official vaillant view is on opening the CC on a service if the CO2 is correct and no other problems are seen?

Tony
 
Joined
23 Feb 2007
Messages
538
Reaction score
0
Location
Hampshire
Country
United Kingdom
Agile said:
In most cases problems are not predictable and are sometimes caused by unpredictable behavour by the occupiers.

What sort of unpredictable behaviour, Tony? Surely, there aren't that many different ways to use a tap - or a shower?
 
Joined
9 May 2007
Messages
883
Reaction score
0
Country
United Kingdom
It always amazes me why people want a thermostatic shower..why? What`s the point? Unless you are going for a razzle dazzle power shower or live in a huge house where hot & cold supplies may be an issue. Why?
They are normally hideous in a 3 bedroom semi detached joe bloggs crib,
so what is the point?
Give me an Eleccy monster any day,Easy, peasy lemon etc.:cool:
 
Sponsored Links
Top