Advice on showers required.

[Vormulac]

Morning folks.

We are having our leaking boiler replaced at the moment, and I've just heard from the missus that the plumber says our current shower is not going to be suitable. We are going from an old boiler/tank system to a combi-boiler system and the current shower is power shower (it doesn't heat the water, it has hot and cold from the house supply but boosts the pressure by way of a pump).
Now I have no idea what sort of shower I can get which is going to give us power shower performance but is compatible with a combi-boiler system.

Does anyone have any knowledge on this?

Cheers!

 

[wizer]

AFAIK you just need a standard shower unit with hot/cold controls. Your shower will be mains pressure. Furthermore AFAIK you can have a tank just for the shower and the power pump can still be used on that.

Our resident plumbers will be along soon for a more coherent view.

 

[Mattty]

Wait until the boiler is fitted it will probably still work.
Depending on many factors including the flow rate of your new boiler and the height of your shower compared to your boiler and your cold mains pressure.
HTH

 

[Woody Alan]

As Wizer says some definitive answers will be along. For the time being mull over this option. Remove pump and connect pipes direct, the shower mixer should already be a high pressure unit as it was a power shower. The next thing to consider is although theoretically the hot water is at mains pressure it is restricted to allow the water to heat instantly/constantly. I hope you have bought as high flow rate boiler as budget will allow. It may be neccessary to restrict the cold water pressure to the shower mixer to be able to balance the hot and cold pressures. There are cheap and expensive ways to do this.

Alan

 

[wizer]

We was lucky at our old place to have very good mains pressure. Only did we realise this when the plumber fitted the central heating system and said that our mains pressure tap had been set really low :roll: :wink:

Current house the pressure is mediocre and I miss the luxury of a brand new system with a high pressure shower. The plumbing has been bodged and DIY'd for so many years that I don't trust it one bit.

 

[jasonB]

Your shower will now be fed by mains cold/hot and it is against water regs to pump mains water so you cant use it as is.

You need to select a mixer that is combi compatible as the combi can only flow a set volume of hot but the cold volume is unrestricted unless you want to start playing about with balancing valves.

Screwfix do a couple by Moretti that are OK with combis.

using it without the power (pump) turned on will not give good flow as you are forcing water through a stationay impellor and again it wont be balanced flow

Jason

 

[jaymar]

We recently had a new boiler fitted and the plumber was emphatic that our power shower had to go. He fitted a Bar Shower and it is fantastic. One control for the temperature (thermostatic)and one for the flow/pressure. The only drawback we have found is that hot water seems to take an age to arrive in the bathroom.

 

[Stollo]

We had a new combi condensing boiler fitted about 18 months ago prior to that we had a back boiler for central heating and a multipoint heater for the hot water. Our shower over the bath used a standard mixer tap setup (non-thermostatic) and was absolutely fine on the old system giving us constant hot water virtually from the start and never varied however long the shower took. Not so with the new boiler, the water starts off at the right temperature then after about 4 mins the water cools off by quite a few degrees, sometimes so much that you have to get out of the flow, it then runs warm again and cycles like this every 2 mins or so. The boiler is made by Ideal and was fitted by British Gas and has the capacity to easily deal with all our needs according to the literature.

I read with interest JasonB's input and wondering if a combi compatible mixer is the answer for us - I'd never heard of them. British gas have tested our boiler and it is doing what it is supposed to do in relation to heating water by so many degrees, but we are certainly not happy with the shower now and have been considering going electric on that.

Maybe one of you has had similar problems and has sorted it - please tell. Sorry I guess this looks like a bit of a hijack on the thread but really could do with good advice and you guys seem to understand what's going on better than I do.

Dave

 

[Doug B]

Vormulac.
What make is your present shower valve? It should be possible (if necessary) to change the cartridge in the valve to a high pressure thermostatic one. That way all you need to do is remove the pump.
James.

 

[Doug B]

Stollo.
I wouldn`t recommend using a non-thermostatic shower off a combi.
If you want to stick with a bath shower mixer, Aqualisa make a thermostatic one. It`s a little bulky but gives an excellent shower.
Once you`ve had a shower off a combi changing to an electric is very disappointing, with regard to performance.
James.

 

[les chicken]

There is another aspect to this thread. ie. How good and reliable are combi boilers. There are so many problems that some of my friends and reports that I have read.

Pressurised systems constantly need topping up manualy

Inconsistant water temperature.

Breaking down.

In our house we have two separate boilers, a 72000 btu thermostatic output for the hot water ( it must be thermostatic output to run a shower off ) and a bogstandard boiler with top up tank which doubles as the heat expansion for the central heating.

Advantages.
Constant supply of hot water at a temp that you set at the boiler.

If a radiator is removed and then replaced, the system tops itself back up automatically and the radiiator only needs bleeding.

All this allows the average DIYer to decorate or alter things without having to call in an expert.

Plus with simple type boilers there is less to go wrong.

You still need a manual temp controlled mixing head for the shower, but it works better because the boiler gives a constant temp controlled water supply.

Just my opinion but we have no problems.

Les

 

[jasonB]

Vormulac

Can you confirm if the pump is separate from the mixer or as I suspect from your description it is a "white box" on the wall fed by gravity hot and cold and the pump is withing the box.

What some people are suggesting will possibly only work with a separate pump.

Jason

 

[jaymar]

I was in Lidl earlier and they have a valve in their catalogue/flyer. It was less than £30.

 

[Stollo]

Stollo.
I wouldn`t recommend using a non-thermostatic shower off a combi.
If you want to stick with a bath shower mixer, Aqualisa make a thermostatic one. It`s a little bulky but gives an excellent shower.
Once you`ve had a shower off a combi changing to an electric is very disappointing, with regard to performance.
James.

James thanks for the info. I've checked the Aqualisa brand out and they seem excellent quality but expensive, I shall be doing a bit more research before taking the plunge. Thanks again.

Dave

 

[Vormulac]

I can't remember what make the shower is, it's a great big long white thing that I connected to the water pipes and the power cable coming out of the wall - it was on special offer in Homebase about 3-4 years ago.

Right, tons of useful stuff so far here, I shall see if I can find a thermostatic one that looks like something SWMBO would like. A pity there don't appear to be any suitable ones that are big white boxes like power showers are, it means I'm going to have a whole load of making good and re-tiling to do once I fit the new shower.

Many thanks for all your comments guys, it's all helpful.

 

[Doug B]

I can't remember what make the shower is, it's a great big long white thing that I connected to the water pipes and the power cable coming out of the wall - it was on special offer in Homebase about 3-4 years ago.

Right, tons of useful stuff so far here, I shall see if I can find a thermostatic one that looks like something SWMBO would like. A pity there don't appear to be any suitable ones that are big white boxes like power showers are, it means I'm going to have a whole load of making good and re-tiling to do once I fit the new shower.

Many thanks for all your comments guys, it's all helpful.

Sorry, thought from your first post it was a separate pump & valve. Looks like you`ll have to replace the original. Thermostatic bar valves are very cheap these days, Bristan do them with easy fit kits.
James.

 

[Harbo]

I was all set to have power shower fitted but my plumber recommended one of these:

http://www.trevishowers.co.uk/trevi_products/mixer_showers/trevi_boost.html

They are fantastic and gives a great flow without any moving parts or noisy motors. It works on the venturi principle - the cold water pressure dragging the hot through at an increased flow.

Rod

 

[Doug B]

I was all set to have power shower fitted but my plumber recommended one of these:

http://www.trevishowers.co.uk/trevi_products/mixer_showers/trevi_boost.html

They are fantastic and gives a great flow without any moving parts or noisy motors. It works on the venturi principle - the cold water pressure dragging the hot through at an increased flow.

Rod

Excellent showers Rod, but not suitable for combi boilers.
James.

 

[RogerS]

There is another aspect to this thread. ie. How good and reliable are combi boilers. There are so many problems that some of my friends and reports that I have read.

Pressurised systems constantly need topping up manualy

Not unless the system has been installed badly.

Inconsistant water temperature.

Breaking down.

......

Les

Most of these problems have been ironed out. A similar question was asked on the askthetrades forum and there were four makes recommended by the guys over there. Judging by the number of posts, baxi seem to need avoiding.

Crucial is adequate mains pressure and volume of mains water available.

Vormulac - if you are retrofitting your boiler you may need to fit a reducing valve in the (probable) 22mm pipes feeding your bath otherwise whenever it is run it will starve the rest of the system.

Combis have their uses but at the end of the day, you are relying on a heat exchanger to heat the water as it passes through.

 

[matt]

Morning folks.

We are having our leaking boiler replaced at the moment, and I've just heard from the missus that the plumber says our current shower is not going to be suitable. We are going from an old boiler/tank system to a combi-boiler system and the current shower is power shower (it doesn't heat the water, it has hot and cold from the house supply but boosts the pressure by way of a pump).
Now I have no idea what sort of shower I can get which is going to give us power shower performance but is compatible with a combi-boiler system.

Does anyone have any knowledge on this?

Cheers!

Not read the whole post but noticed your location. Recommend a visit to Potter Perrin in Streatham (opposite the common). Good range, good advice, good prices.