Installing two showers
- Thread starter cooperman
- Start date
and the hot water system is 
As kev says, you will need to explain what hot water system you have, or intend to have.
1) 2 Electric showers are generally a no-no in a domestic situation. The power draw would be excessive, and the mains water pressure would be likely to be insufficient.
2) A combi will not be sufficient, despite the fact that they are about twice as powerful as electric showers (you will find the flow less than a dribble)
Which leaves two solutions: gravity, or unvented cylinder. I have no idea about unvented cylinders, and it is a job for the pros to have on installed. Perhaps they can explain.
With a gravity system, it is easy. However, if you intend to use two showers simultaneously you will need to have a large supply of hot water, and an even larger supply of cold water. Even with a relatively mediocre shower pump it is possibly to get through a whole tank of hot water in one shower. So, I would reckon you will need something pretty hardcore to supply two showers simultaneously.
1) 2 Electric showers are generally a no-no in a domestic situation. The power draw would be excessive, and the mains water pressure would be likely to be insufficient.
2) A combi will not be sufficient, despite the fact that they are about twice as powerful as electric showers (you will find the flow less than a dribble)
Which leaves two solutions: gravity, or unvented cylinder. I have no idea about unvented cylinders, and it is a job for the pros to have on installed. Perhaps they can explain.
With a gravity system, it is easy. However, if you intend to use two showers simultaneously you will need to have a large supply of hot water, and an even larger supply of cold water. Even with a relatively mediocre shower pump it is possibly to get through a whole tank of hot water in one shower. So, I would reckon you will need something pretty hardcore to supply two showers simultaneously.
- Joined
- 10 Jul 2004
- Messages
- 15,680
- Reaction score
- 6,053
- Country
Boiler needs replacing, obviously had it's day.
B
breezer
i can see you are not a barrel of laughs, is this a totaly new build? or is it an extension? also read what AdamW wrote
I had thought of doing it like you suggest but I was told that if we were using both at the same time when the water emptied from the cylinder it would be topped up from the header tank which would draw water from the mains thus affecting the pressure to the electric shower
yup 
- Joined
- 10 Jul 2004
- Messages
- 15,680
- Reaction score
- 6,053
- Country
One header tank big enough to supply two showers and rest of demands, two hot water cylinders, then do what you like, gravity or pumped.
... 1) as previously mentioned an unvented cylinder should have sufficient pressure and a sufficient store of hot water to feed both showers at the same time without a lack of pressure.
2) Conventional Vented system with a large CWSC in loft and a good size DHWC with a pump capable of supplying at least 2 showers - somewhere 2-3 bar would be sufficient - 3 bar preferable.
In a refurb I would be tempted to put in an unvented system as this has many benefits over the second option above. A pump is a solution to a problem caused by a flawed system - seems silly to put this system in when you know it wont be sufficient without the addition of a pump.
Plus it will save you messing about with a large CWSC in the loft taking up space. Combine it with a sealed CH system then no tanks in the loft whatsoever.
2) Conventional Vented system with a large CWSC in loft and a good size DHWC with a pump capable of supplying at least 2 showers - somewhere 2-3 bar would be sufficient - 3 bar preferable.
In a refurb I would be tempted to put in an unvented system as this has many benefits over the second option above. A pump is a solution to a problem caused by a flawed system - seems silly to put this system in when you know it wont be sufficient without the addition of a pump.
Plus it will save you messing about with a large CWSC in the loft taking up space. Combine it with a sealed CH system then no tanks in the loft whatsoever.
I really do not understand the replies I have read. Some five years ago I converted a very large upstairs playroom into two large bedrooms with ensuites. The distance from the "tanks" in my vented system was such that the showers hardly trickled.
Thanks to help from Bahco, if I remember right, I connected the two ensuites onto a very cheap purple pump (Showerstream £95?) from B&Q, it could be adjusted as to outflow pressure. It has been superb, both my kids use it regularly at the same time, but I did make the decision not to have it on full power but the shower force is still very acceptable.
2 years ago I connected our own ensuite onto the same system, from a gravity fed previously, no problem.
The main bathroom has a gravity fed shower that is connected via a different set of pipes to the water tanks. So very occasionally when my daughter is home three showers can be on the go, and I have yet to run out of hot water.
Now we do not have "power showers", the hot water tank never lets us down, and the shower forces are more than acceptable. The only time I have a power shower is when everyone is out and I secretly turn the pump adjustment to full, the pump is in the airing cupboard next to our bathroom - have to have a treat sometimes!!
I am no plumber, just been grateful for all the help they have given me on the site here, invaluable - but I can speak from what I did and it worked, and the pump still goes on happily, guess I must be lucky!!
Thanks to help from Bahco, if I remember right, I connected the two ensuites onto a very cheap purple pump (Showerstream £95?) from B&Q, it could be adjusted as to outflow pressure. It has been superb, both my kids use it regularly at the same time, but I did make the decision not to have it on full power but the shower force is still very acceptable.
2 years ago I connected our own ensuite onto the same system, from a gravity fed previously, no problem.
The main bathroom has a gravity fed shower that is connected via a different set of pipes to the water tanks. So very occasionally when my daughter is home three showers can be on the go, and I have yet to run out of hot water.
Now we do not have "power showers", the hot water tank never lets us down, and the shower forces are more than acceptable. The only time I have a power shower is when everyone is out and I secretly turn the pump adjustment to full, the pump is in the airing cupboard next to our bathroom - have to have a treat sometimes!!
I am no plumber, just been grateful for all the help they have given me on the site here, invaluable - but I can speak from what I did and it worked, and the pump still goes on happily, guess I must be lucky!!
You aren't lucky, its a perfectly acceptable solution to your problem. I fit many shower pumps for customers in your position.
HOWEVER: the OP stated that this is a "new installation" and therefore the best system for his requirements from what he has told us would be to install an unvented system.
If he merely wanted up add bathrooms in and get decent showers then a pump is the solution - if however he wants to install a new plumbing system which is what I have understood from his posts then the correct advice to him for the most appropriate and up-to-date system to fulfil his requirements is an Unvented Cylinder along with a sealed system for the central heating.
Performance wise it is far superior to a vented system and will handle whatever he wishes to throw at it in the future.
SIMPLES
HOWEVER: the OP stated that this is a "new installation" and therefore the best system for his requirements from what he has told us would be to install an unvented system.
If he merely wanted up add bathrooms in and get decent showers then a pump is the solution - if however he wants to install a new plumbing system which is what I have understood from his posts then the correct advice to him for the most appropriate and up-to-date system to fulfil his requirements is an Unvented Cylinder along with a sealed system for the central heating.
Performance wise it is far superior to a vented system and will handle whatever he wishes to throw at it in the future.
SIMPLES
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
