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rocketmanbkk

Plumbers Arms member
Plumber
Apr 27, 2011
4,106
903
113
Langley, Berkshire
Dear Friends

My Mum is 80 this year and she's had low pressure to the bath taps (just told me!) for ages.

In her 1st floor airing cupboard is her tank and the cwsc directly connected.

If I was to put a pump in and connect to the bath taps would this solve the issue? She has electric in the airing cupboard.

Or is it better to put a new tank in and put a tank in the loft to give more head height?

Cheapest solution really.

Best regards

Rocket.
 
Thanks for the reply. She doesn't have a combi. I thought about the taps, she is not keen!!! I'll have a look for another set of mixers with shower attach as she has now.

Best regards
 
i did not mean a combination boiler but a combination cylinder (cylinder with tank sat on top). most mixer taps will have poor flow compared to a standard single tap. It may be cheaper to get a electric shower installed.
 
Sorry! Misunderstood.

The combit tank is now in the airing cupboard. Would it be tetter to change so that the tank have a CWSC in the loft to give it more pressure? Or do you mean to put the whole combi system in the attic? ( I don't think it will fit through the access hatch).

Thanks for advice on mixer taps also, wasn't aware they had less pressure as the ones put were for low pressure systems. When she had single taps, all was fine. May just change taps to pillar taps but she'll have to go back to the old fashoined rubber hose unit to wash her hair.
 
The easiest thing to do is as Awheating said. Just a matter of extending the pipes then and it will increase the head by a couple of meters.
If you want to put a new cwsc in the loft you will need a new cylinder too. A lot of expense for little gain. If the cylinder won't fit through the hatch cut it bigger.

No matter what shower attachment you fit it won't work if you lift it up higher than the combination cylinder. You can't pump from a combination tank either.
 
OK, what I think I'll do 1st is change her taps back as she was happy before.

If not good, I'll buy a new tavk and cwsc and remove old conmbi, put tank in airing and cwsc in loft.

Should be a winner, more expense but I need her happy, she's me mum!!

Thanks again for the reply.
 
Moving the combination tank to the loft will give you more head unless you build a tank stool. It will also work just as well.
 
My Dad had a similar situation, if you were standing in the bath the water height in the CWSC was around eye level. A Triton AS2000XT Thermostatic Power Shower has done a great job for a number of years.
 
Moving the combination tank to the loft will give you more head unless you build a tank stool. It will also work just as well.

Would this not be negligible though? The head in this case will be operating on the distance between the water level in the cwsc and the connected cylinder. Therefore being the same whether in the loft or on the roof. There may be a small advantage gained from an increased drop on the pipework but imo not worthy of the effort involved.

Sent from my GT-I9100 using Tapatalk
 
you've lost me with that one mate!


talking about the benefit or lack thereof of moving the combination cylinder to the loft.
if it wasn't a combination cylinder pressure could be increased by raising the cwsc as high as poss above the cylinder ie in loft. but with the combi cylinder in loft you aren't really increasing head (standing pressure) because the cylinder is being raised as well as the cwsc because they are conjoined.
 
sounds like the problem is reduced pressure due to a limited head of water, but scale build up in the pipes over time can cause similar issues
 
what he means if the you had a seperate cwsc the higher you can raise it above the cylinder the greater the pressure into the cylinder thus giving greater pressure to the taps but as its all in one you cant increase the the pressure to the cylinder no matter how high you lift it
 
what he means if the you had a seperate cwsc the higher you can raise it above the cylinder the greater the pressure into the cylinder thus giving greater pressure to the taps but as its all in one you cant increase the the pressure to the cylinder no matter how high you lift it

correct, or at least that is my understanding of it.
 
Would this not be negligible though? The head in this case will be operating on the distance between the water level in the cwsc and the connected cylinder. Therefore being the same whether in the loft or on the roof. There may be a small advantage gained from an increased drop on the pipework but imo not worthy of the effort involved.

The height of the cwsc above the cylinder is irrelevant to the head of water (pressure) available at the taps as it just runs through it.
The head at the taps is determined by the height of the cwsc, or in this case the water level in the combination cylinder, above them.
A combination tank will not give any less pressure at the taps than a separate tank and cylinder. The higher you lift it the better the head of water so it is worth doing.

Think of it like this.
A cwsc fitted in the loft of a 3 story building, 3m ceilings, and the hot water cylinder fitted on the floor of the ground floor and a shower head on the top floor.
Discounting pressure drop due to resistance, the pressure on the bottom of the hwc would be just under a bar. The pressure at the hot tap on the ground floor perhaps about 0.85 bar, the pressure at the shower head would be around 0.1 bar.
Same scenario with a combination cylinder in the loft, The pressure at the bottom of the cylinder would be around 0.08 bar, pressure at the hot tap on the ground floor is the same 0.85 bar and same 0.1bar at the shower head.
Same pressure at the outlets.
 
Last edited by a moderator:
agree with Tamz about the pressure,
possible issue with complete combi move to loft space is suffient structure to carry the combined weight
 
So, as Tamz and others say, it would be better to to fix a tank in airing cupboard and new cwsc in loft to provide better pressure to bath taps.

It's as I thought and wanted to thank all for their comments.

I'll see what she wants to do but want to get it done for her as a bath takes a lifetime to fill.

Thanks again
 
The height of the cwsc above the cylinder is irrelevant to the head of water (pressure) available at the taps as it just runs through it.
The head at the taps is determined by the height of the cwsc, or in this case the water level in the combination cylinder, above them.
A combination tank will not give any less pressure at the taps than a separate tank and cylinder. The higher you lift it the better the head of water so it is worth doing.

Think of it like this.
A cwsc fitted in the loft of a 3 story building, 3m ceilings, and the hot water cylinder fitted on the floor of the ground floor and a shower head on the top floor.
Discounting pressure drop due to resistance, the pressure on the bottom of the hwc would be just under a bar. The pressure at the hot tap on the ground floor perhaps about 0.85 bar, the pressure at the shower head would be around 0.1 bar.
Same scenario with a combination cylinder in the loft, The pressure at the bottom of the cylinder would be around 0.08 bar, pressure at the hot tap on the ground floor is the same 0.85 bar and same 0.1bar at the shower head.
Same pressure at the outlets.

Thanks tamz makes sense, was thrown at first cos its contrary to what i was taught.

Sent from my GT-I9100 using Tapatalk
 
What would happen in reality if you sat a combination cylinder in the loft in the above scenario and opened the hot tap on the ground floor is that it would draw air as the water would run out the cylinder faster than it could fill due to the pressure difference.
If you ever have to sit a hwc under a cwsc in a loft use a 28mm feed to the cylinder to overcome this.
 

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