RM Combination indirect cylinder hot take off for shower advice please

[Volunteer]

Hi, I need to get a 22mm hot feed from a RM Combination Indirect Tank/Cylinder, fitted in the loft, to a shower mixer. The existing hot out connection is on the SIDE of the cylinder (no vertical outlet pipe/vent because cold header tank is fixed to the top of the cylinder) To mitigate possible air bubble problems I was thinking I might modify the existing horizontal outlet pipe by turning it up from the cylinder side at about 30 degrees, then T off to shower then T off to taps with an Automatic Air vent in the top leg of the final T. Will this help to expel the potential air bubbles? Does any one see potential issues with this idea. Many Thanks

 

[Ray Stafford]

Hi Volunteer

Normally when people are worried about air bubbles from a cylinder, its because they are pumping the supply to the shower.

Are you pumping the hot from this combination tank? If so, you have a bigger problem to worry about than a few air bubbles!

Ray

 

[Volunteer]

Hi Ray, Yes that is hopefully the plan. I intend to link an additional 25 gallon cold storage tank to the combi inbuilt 40 tank (which is only 40 litres) . The cold supply to the pump will be taken from a separate 25 gallon tank, which is already installed in the loft alongside the bottom of the cylinder , and feeding the bath mixer tap.

 

[Ray Stafford]

I'm struggling a bit to envisage this.

The combination tank is in the loft, and there is an existing 25 gall CWS tank in the same loft. You are planning to add an additional 25 gall tank linked to the cold part of the combination tank - so are you putting that on a stand? How are you planning to link the two?

I dont mean to sound unduly critical - after all, I haven't seen it - but it sounds a bit of a lash up tbh.

Surely there's a simpler solution?

 

[stevetheplumber]

dont see how you intend to link another tank to the combi cylinder as no pipework on it is normal sizes if you have the room to fit a tank high enough to be above a combi cylinder you can easily get a normal cylinder under it unless your planning on using bodyjets or a high preasure shower which needs a pump 6 ft of head will give you a nice shower if you use the right mixer