• Welcome to PlumbersForums.net - The international free plumbing advice forum. Professional plumbers sharing advice with fellow plumbers and DIY alike. Register for free today! - Checkout the Plumbing Advice forum and then our Plumbing Videos area which still needs populating.

Discuss Different flow temperature for radiators and hot water tank circuits in the Gas Engineers Forum area at PlumbersForums.net

Gorge123

Messages
1
Hi Morning, I am looking at a new boiler and hot water cylinder setup for a house I am refurbishing and am getting conflicting advice on my question: Can I use a Combi or System boiler to have a different flow temperature for the hot water tank heater and the radiators. I appreciate the hw cylinder needs a minimum of 65C, which for most days is overkill for the radiators, which I deliberately oversize to run on a lower flow temperature. Appreciate any helpful advice on here!
 

Chuck

Esteemed
Messages
2,613
Depends on the specifics of the boiler model and controls. For example, some Worcester Bosch Greenstar boilers can do what you want but they have to have an optional internal diverter valve kit fitted, which adds to the cost. If the radiators are oversized you should be able to run them with 65°C flow and achieve a return of 50°C or below but you'll need to spend a few hours making sure the system is correctly balanced. If you want an efficient system and a comfortable home, the boiler's minimum output is a key parameter that is often overlooked (the lower the better).

A competent installer should be able to take you through the options and the pros and cons of each configuration.
 

ShaunCorbs

Staff member
S. Mod
Plumber
Gas Engineer
Messages
32,385
Solutions
3
System boiler and either a 4 pipe system eg Viessmann (or 3 pipe with a diverter eg Worcester) or a boiler this accepts two switch lives eg ideal vouge system and oversize rads to run at a 45 dc flow temp
 

Reply to Different flow temperature for radiators and hot water tank circuits in the Gas Engineers Forum area at PlumbersForums.net

Similar threads

B
Ensure you check out the pump setting before doing anything else especially if you had no pumpover with the old pump, lots of people had this...
Replies
12
Views
664
John.g
J
D
Yes and you can go even further add an outside weather comp box to the heating side this will adjust the flow automatically once set up to match...
Replies
1
Views
197
ShaunCorbs
ShaunCorbs
R
OK back early. Too cold! Boiler (hot water) has been running since early this morning (7am) its now 23:00. Boiler running fine. Radiators mid warm...
Replies
19
Views
385
Rincewindwiz
R
Ted808
I can't think of a single-component cause but, if I've understood the OP's observations correctly and the pressure changes are relatively rapid, a...
Replies
3
Views
128
Chuck
C
Spinball
  • Question
Thanks. It’s pretty powerful. At least 3 bar, I would say. It feels as powerful as in my last house which was measured at around 4 bar when we...
Replies
15
Views
272
Spinball
Spinball
Creating content since 2001. Untold Media is a Registered Trademark.

Newest Threads (Please Reply)

Search Forum

Top