1/2 inch pipe in central heating

demanufactured

Hi

Having looked over my central heating system (solid fuel) ,it seems that there is a lot of 1/2 inch pipe used in the circut.

Let me explain...

Running from the stove is 3/4" flow and return pipes, upto the cylender and then on to the first upstairs rad , which is teed off with 1/2 inch as normal.

Then on from this is a short run of 3/4" to the middle of the landing, this is where it gets complicated.

From here there is a pair of 3/4 x 1/2 x 1/2 tees , one pair of 1/2 inch pipes going to serve the 2 rads in the master bedroom , and the other is an inverted pipe loop for the 3 downstairs rads , all of which is 1/2 inch copper.

The rads heat fine fore the most part , the last rad in the upstairs curcut sometimes needs bleeding.

There was origionaly only 2 rads downstairs but i added the third for the sitting room , i teed directly off the 1/2 inch copper coming out of the floor in the hall.

Te new rad dosent seem to heat as well as the old ones.

Should i change this 1/2 inch for 3/4 inch as i think it might improve the system and quiet it down a bit , (you can hear the water flowing through the rads from all over the house.)

Soirry for the long post.

MiniGolf

System needs to be balanced..... this should reduce the noise and even up the heat distribution among the rads and hot water. The noise could also be attributed to a noisey circulating pump being "amplified" by the water in the system.
To answer your question about fitting a 3/4" pipe instead of 1/2" the answer is yes! It will help the flow to the rads on that circuit.:)

darcy.jonny

if your question is >>> changing the 1/2 pipe you installed to 3/4 the answer is a definitate no . under no cirsumstances go from a 1/2 feed and increase to 3/4 ....... you will destroy the systems circulation and balance.

if the question is replace the 1/2 throughout .......... then yes but only on the primary flow and return . with each rad having a seperate 1/2 feed for both flow and return .

the noise in your system can be caused by : as minigolf said a noisy pump , dirrt and sedement circulating around the system , but more likely if you bleeding the radiator upstairs often ......... its air

the reason why your rad is not heating is the system is off balanced .

erm to explain this the best i can simply ermmm.... turn on the heating at its max setting turn up any thermostat that you may have to maxium go to each rad in the house and close both the flow and return valves (turn off both rad valves ) go to the hotpress and turn off the 3/4 valve going to the heating coil (taking note how much it is open .. turn wise )

go to the new rad and open both both valves either side, wait a few minutes and you should feel the rad heating up if the piping was done correctly .

if the rad gets hot go first back to the hotpress and open the valve slowley , im the majority of cases the valve on the cylinder coil need only a small qualter to half turn to opperate sufficently .... to check this open a lil bit at a time .... put your hands on both pipes from the cylinder coil . if both sides feel hot then job done .of
go back to each rad that has been turned off . but this time use the method applied to the cylinder open the lockshield side of the rad (the valve that cant be turned of by way of plastic head , open this roughly a half turn in a lot of cases you will feel when the valve is open . after this go to the flow side and open slowly following the same method . feel both valves either side and if they start to warm up move on to the next rad.

its a slow process but it will work and will increase the efficency of your system get the rad going and may just save you a few bob . if the rooms are not warm enough to your liking , just open the vales a little bit at a time when your happy .. a lil trick is to get a thin marker and where it cant be seen draw a line from the head onto the valve . this will allow you to close off the valve if you like but show you where exactly you had it when open .

if the balancing fails depending on your system ... there could be a build up of sedement in your system . especially if uve just deained it down to add aditional pipe and rads. a chemical cleaning of the system will need to be carried out ..................... and to be honest go get yourself a bottle of inhibbitor and add itto your system .... its reletavily inexpensive and will protect against further corrosion (youve just put fresh water in the system when you filled it up ) and prolong the life of your rads , heatxchanger etc.

if your stuck pm me and ill send you my number and talk you through it (if im not up to my eyes at the time lol)