Forums

Forums
Renewable Heating
Domestic Hot Water ...
Location of hot wat...
 
Notifications
Clear all

Location of hot water isolation valve on cylinder

 
Domestic Hot Water & Cylinders
Last Post by rossowheels 3 weeks ago
4 Posts
3 Users
2 Reactions
83 Views
RSS
 rossowheels
(@rossowheels)
Active Member Member
Joined: 4 weeks ago
Posts: 2
Topic starter 05/07/2025 6:57 pm  
IMG 2123 Original
IMG 2122 Original

I have recently moved to a property with a heat pump and would like to isolate the hot water supply to the bathroom in order to carry our renovations. The WC and basin have isolation valves but the bath does not (check valves only).

Would very much appreciate any advice.

This topic was modified 4 weeks ago by Mars

   
Quote
 ASHP-BOBBA
(@ashp-bobba)
Honorable Member Member
Joined: 8 months ago
Posts: 203
05/07/2025 10:40 pm  

@rossowheels if you isolate the water supply in it will stop the flow to the hot water on all circuits, any circuits lower than the tank will need draining, to do this you must open all hot water taps in the house to prevent an air lock, this will allow the air in at high level to ensure the low level taps are empty.

Professional installer. Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.


   
👍
1
ReplyQuote
Transparent
 Transparent
(@transparent)
Illustrious Member Moderator
Joined: 4 years ago
Posts: 2438
07/07/2025 8:14 pm  

@rossowheels  the convention is that there should be a Gate Valve on the cold supply into the Domestic Hot Water Tank.
This is sometimes labeled DHW - Cold Feed because all plumbers & heating engineers will understand that.

A gate valve has a metal wheel which slides a brass disc across the bore of the pipe.
Thus it is a "full bore" valve... one which doesn't constrain the water flow when open.

image

A valve in that position allows you to drain the entire hot water system, replace or add further isolation valves, change the immersion heater, or even the entire tank.

Have a look and see if you have such a valve.
If not, then now is a good time to drain the system and fit one!

Save energy... recycle electrons!


   
ReplyQuote
 rossowheels
(@rossowheels)
Active Member Member
Joined: 4 weeks ago
Posts: 2
Topic starter 07/07/2025 9:04 pm  

@transparent Thank you so much and very helpful. Earlier today I decided to shut the system down completely, turn off the main stop cock under the sink and open all the taps. The system drained down very quickly surprisingly but now don’t have any water until the pipe work is rearranged in the basement!


   
😢
1
ReplyQuote
Forum Jump:
  Previous Topic
Next Topic  
Share:

Join Us!

RHH Awards

👉 Vote for “Heat Pump of the Year”

👉 Vote for “Best Manufacturer Customer Support”

👉 Nominate “Heat Pump Installation of Year”, “Best New Tech or Innovation” or “Turkey of the Year” here!

Latest Posts

Members Online