As a first time buyer I assume we had a very basic checklist that the estate agent has seen throughout their career on a daily basis. Roof looks alright? Check. Does it need a rewire? Check. No artex ceiling? Check. Okay boiler? Check.
Well I never thought we’d have to be aware enough of how many radiators there was in the house. After exchanging contracts and moving in, we realised one of the two bigger bedrooms didn’t actually have a radiator! There was also a lock on the door to this bedroom. Maybe the previous owner’s grandkids didn’t get supper or heating if they put up a fuss?!
This is our guest room currently but will be the room for the newcomer to the family. Previously we had an electric heater in this room before renovating the house. It was time to add a new radiator. Eventually I saved up enough to convert them into smart radiators!
Location of adding a radiator
Whilst the location of the house is important for it’s value, the location of each radiator is also pretty important. Some may cut corners and add it to walls which don’t make sense. This would be to reduce the amount of work required for the plumbing. The general consensus is that the best place for a radiator is under the window. In those frosty mornings when the cold is beating down onto the glass and into the room, you want the heat rising from the radiator below to mix with the cold coming into the room. It also visually looks more appealing there and is generally space you might not be using anything. It definitely was an unusable wall for us because of how low down our windows are on the first floor!
Joist direction
So after deciding where the additional radiator was going, it was time to look at joists. The best way to add a heating line is to run off existing pipes to the existing radiators. If you want the pipes to go against the joists from say an adjacent bedroom, then that will be a lot of notching and making holes. By cutting holes in the joists it could compromise it’s strength and there are rules regarding how high, how big and how many you can do on the joist.
Without wanting to get into structural engineering it was easier to work from pipes that were already in the same section but considerably further away from the window location. This meant that I wouldn’t have to make any notches in the joists even though the study next door had a radiator right next to it.
The 5 metre run
The master bedroom was the first radiator on the floor to be fed by the boiler, the flow and return both work their way around the room and go into the study. The downstairs feed goes off from near the boiler so we can view that as a separate line. As previously mentioned, the study was physically a lot closer to the cold room than the master, but as the master was parallel to the cold room it meant
no structural compromise. The only issue was to join the pipes would require a 5 metre run! Now this wouldn’t be too much of an issue if using plastic piping, which today I would thoroughly recommend if I were to do it again. I however went traditional and kept it copper. Also if I was lazy I could have just had the radiator on the wall opposite the window. That would mean just less than a metre to the original pipe but the room would be compromised in heating. It would also make that wall less flexible to do what you want with it. In our case it was putting a bed there into the alcove (I haven’t drawn the alcoves in).
Pre soldering
As I’ve said in a previous post, you get your best soldering done when it’s out in the open and you’re not crawling around the floor to get the heat distribution perfect. I bought two times two lengths of 2 and 3 metre 15 mm copper pipes which would take me all the way to the end of the cold room, right under the window.
I soldered them with Yorkshire fitting connectors.
Getting the pipes under the floor.
How do you put a 5 metre run of non flexible copper under the floor? With great difficulty! I had to remove about 4 rows of floorboards in order to get a good angle of the tip of the pipe run. The back of the pipe actually had to hang out the open window as I fed it into the floor! To avoid picking up 101 years of lat and plaster muck, I taped the end as I was shoving the pipe back and forth to move over all the crud.
Checking for leaks.
I guess if I was a pro I probably wouldn’t need to do this. Or I’d have the equipment to test for leaks before laying pipes down. Now there were two soldered connections now under the floor in the cold room. I removed the floorboards in there to find these connections. Once I’d fill up the system, they would be two additional points I would go and check out to see if there were any leaks. If I hadn’t, the worst case scenario would be a leak and coming through into the living room below.
Finishing up
I added 90 degree elbows and then some more straight pipes to bring them up to the radiator which was already hung with it’s valves in. I made sure to have some leeway for awkward angles and floorboards.
Things to take note when adding a radiator
- Generally the heat and flow return pipes are at 22 mm and then go off into 15 mm runs to each bedroom. Whilst not always the case there are also micro bore systems which were popular in the 70s I think due to being flexible so less connections were needed- you could fit a whole house a fraction of the time.
- So the point you need to consider is if the pipes feeding the radiators are 10 mm, then you will struggle getting heat out of it when it splits to two. You’d then have to work back and take a connection at an earlier point. I still took a connection from a 15 mm point because it was just one addition to the two radiators. After heat testing the rooms all heated up fine.
- When hanging the radiator, make sure to account for increased width once the valves are in place. As long as the ends on each side plus 45 mm(ish) doesn’t seem tight against a joist, then you’re okay. If you were hanging and it was already close to a joist on one side, counting for the valve after may mean you have the pipe in the wrong straight run of a joist and will need to cut a hole through to connect. Or worse, you’ve got some crazy snakey twist above the floorboard to get to the valve!
- Of course you need to have the central heating drained if you want to make modifications otherwise you’ll have nearly 2 bars of pressurised dirty water to play with!
- Check out how I split my central heating to incorporate wet underfloor heating.