zone control using 2 port valves

J

jamesBen80

Joined
12 Feb 2017
Messages
84
Reaction score
1
Country
United Kingdom
I've finally had enough of thermostatic rad valves not doing what they said. They either don't shut off fully or the temperature range is so far out they might as well not be on there. Rant over. So i'm thinking of fitting a 2 port valve on the flow to each rad and having it controlled by a descent calibrated thermocouple. The valve opens if it's below the rooms set point and closes if its at or above the set point. Firstly can anyone suggest a maker of 15mm 2 port valves. Also i don't think a soloniod valve would be suitable as they open and close so quickly they could cause excessive noise in the system. Also any other views on this idea?
 
Sponsored Links
Bloody daft idea frankly. But if you absolutely had to.

Standard trv bodies with MT4 thermoelectric actuators linked to a receiver linked to a thermostat.

Or you could do it properly as above.

Honeywell valencia valves are accurate as are Drayton trv4.

When installed properly.
 
Sponsored Links
Honeywells evohome system looks good at first glance but will cost around £1000 and has a limit of 12 zones. It also rely's on wireless technology which I've found to be unreliable in the past and the TRV's need battery's which will need to be changed regularly. They also look a bit clunky next to the radiators and will suffer the same issue as all TRV's, they detect the temperature next to rad not in the room where your sitting.
As we're in a bungalow, I've got easy access in the loft to the pipe drops into every room where i can install the control valves out of site. I can then mount the temperature sensor somewhere in the room away from the radiators.
I've got 3 radiators in the largest room all with Drayton trv4's on and with them all set at number 3, one is stone cold 1 red hot and the other one warm to touch, I've tried swapping them around and they behave the same and I've also replaced them with 3 new ones and the results are the same just on different rads. I've also tried a few other makes and they are all much the same some not even shutting off on the lowest setting. I've spent days draining the system swapping valves and refilling and bleeding the air out, all to no avail, hence why i'm looking at alternatives. I was going to do something with Arduino (
) as I've some experience with it in the past. I think i will try a couple of rooms as a trial and then extend it to the rest of the house if it proves successful
 
As I've obviously gone wrong someone with this thread can i start from the beginning and ask how i should install a TRV to make sure it works correctly?
 
Start with Decent valves - Honeywell Valencia, then Drayton TRV 4. At a push, Peglar.

Installed preferable on the flow.

Plenty of free air around the rad and valve head to allow air flow.

Radiators don't radiate. (meaningfully)
 
Ok so Friday I went out and brought 3 new Drayton TRV4's from screwfix and fitted them all to the flow side of the 3 radiators in the dining room. All the rads are less than a year old and when i drained them to switch the vales water ran out clean so i know they are not blocked with sludge. 1 rad is a 6 column cast iron 2000mm x 600mm rated at about 15000 BTU's, then there is a 1000mm x 700mm 2 column cast iron rated at about 3000 BTU's and the last one is 1400mm x 600mm 4 column cast iron rated at about 6500 BTU's. Refilled the heating and fired the boiler up, the room was at about 16C and with all the valves set at 3 the largest rad is hot, 1 of the small ones is stone cold and the other is just warm to touch. I turned all 3 TRV's down to 1 and left the door shut to the room and after a couple of hours i went back in to check the room temp and my multimeter was reading nearly 32C. The large rad was quite hot so i assume still had a good flow of water going through it. This time the one that was cold was was very hot to touch and the other one that was warm one was cold? Is there a limit on the size of radiator a TRV can control? i know the 15000 BTU is on the limit for a 15mm pipe, but it's only about 2m of 15mm drops from the main 28mm in the loft so i assumed that would be OK.
 
Sounds like your radiators might need balancing.

Don’t knock evohome until you’ve tried it. It works very well. Batteries in the TRV heads last 2 years; room temperature control even from the TRV heads is excellent (because, as stated above, radiators actually convect most of their heat). 12 zones is rarely a limitation; zones can be multiple rooms or multiple radiators in a room.
 
D

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

 
You must log in or register to reply here.
Sponsored Links

Similar threads

Mike2007
2 port zone valve
Replies
4
Views
1K
ChrisR
ChrisR
N
Honeywell 2 port valve replacement problem
Replies
9
Views
12K
Softus
S
H
2 x 2-port versus 1 x 3-port diverter valve
2
Replies
23
Views
4K
Agile
Agile
W
Converting a V4043H1056 (NC) 2 Port Valve to a V4043B1257 2 Port Valve (NO) ??
Replies
13
Views
1K
Mister Banks
M
R
2 port valve stuck shut..
Replies
2
Views
1K
ianmcd
ianmcd
Back
Top