Thermostatic valves (TRVs) are a great accessory for any radiator. They help you control heat output from room to room, lower energy usage to bring bills down, and take the guesswork out of how hot a room should be.
While they come in all shapes and sizes to look nifty, they are surprisingly simple pieces of kits that don’t use any special technology at all to work. When buying new radiators and valves, you might think that every single radiator needs one or that your home should at least have one TRV in every room. This isn’t necessarily true.
Thanks to the radiator experts at Trade Radiators, who know a thing or two about TRVs, here are some of the key points to know before buying thermostatic radiator valves. Hopefully, they can help you understand why you may be better off without a valve, or at least know if a “broken” valve is working fine.
You Won’t Need these Valves in Every Room
What’s the most important thing to know when buying thermostatic valves? You don’t want to buy them for every room. There is one time when you wouldn’t want a thermostatic valve on a radiator. Suppose the heating controls also have a thermostat setting. In that case, it means it will work away when the heating is on and only tell the boiler to stop when it reaches the desired temperature.
Now, what could prevent the thermostat from ever getting the temperature right? Well, if you have a radiator nearby with a thermostatic valve set low, you’re essentially asking your home heating to do two things at once, with the thermostat and valve fighting each other. Avoid a thermostatic valve for the radiator nearest your thermostat.
If you’re looking at your heating controls and can’t see any option for a thermostat, it usually means the thermostat is attached to the boiler. This is more common in homes that use oil for central heating and would have their boiler outside. If you nip out and see a small box at the front of the boiler with a dial, that’s the thermostat.
Your Existing TRV May Not be Broken
Many people will buy new thermostatic valves because they play around with the valve when heating is on, and nothing happens. You would instinctively think the thing is broken and you need a new one. In reality, the valve may have a problem that is almost too easy to figure out and fix.
If your TRV is unresponsive, turn the valve to the max/ 5 setting (make sure your heating is off). You can then unscrew the top of the valve, and it will come off, showing a pin sticking out. This is what moves up and down as the valve expands/contracts to control heat. These pins are prone to sticking after a while. You can try spraying some lubricant on the pin and trying to push it up and down with any tool at hand. It should move after a few goes and be fine to work again.
If it doesn’t budge at all, you’ll need to get a new TRV.
You are Blocking the TRV
A thermostatic valve needs to gauge the temperature of the air in a room to open and close. If you partially obstruct or fully cover one, it won’t work. The most common example would be when people hang clothes and laundry on radiators to dry. I must point out that this is a really bad idea, as it can add moisture to the wall surrounding a radiator and welcome mould.
Having something like a shirt or sheet hanging on the radiator will also see it cover your TRV. By trapping the valve, it will only pick up the trapped heat rather than the ambient temperature and constantly shut off. Avoid a chilly room by ensuring there is decent airflow around your TRV.
Now Find a Reliable TRV
I hope this brief glimpse into thermostatic problems helps you know whether or not you need to buy a new one soon. Just remember that a TRV is always an accessory to your overall heating system. It may help control independent factors but think of it as a step in the chain of controlling heating throughout your home.