Heating
What we started with
Before we bought the house I thought I'd been quite clever. I had asked the previous owners to power up the central heating and confirmed that the radiators got warm and left it at that. I wasn't that concerned as the boiler and the associated plumbing was only about 6 years old - what could possibly have gone wrong in that amount of time? Quite a lot was apparently the answer....
The first night we properly used the central heating we got a knock on the door. It was one of the neighbours informing us that there was a stream of steaming hot water shooting out of our loft overflow onto the pavement below! Apparently it had been doing this pretty much every day for the last three years. After a bit of investigation it soon became apparent that :-
1. The wall thermostat wasn't actually wired in, so the boiler would just keep going until the timer switched it off. This in it's self, whilst not terribly efficient, wasn't necessarily dangerous (there are plenty of old boilers that don't have a room stat) however the second issue was.
2. The boilers internal thermostat, which basically turns off the gas burners once the water is hot enough had failed. This meant that the water in the central heating system was just getting hot and hotter and closer and closer to boiling point. A quick poke of my head in the loft indicated that the plastic expansion tank in the loft was full of steaming water and it was starting to melt. The only thing stopping it from reaching total meltdown was the emergency thermal cut out switch on the boiler, however if this had failed then we faced the very real possibility of a tank of boiling water pouring on our heads.
At this point the power to the boiler was switched off and we pondered. Having spent what seemed like the equivalent of a small country's GDP on the house, we didn't have any spare cash to call in a plumber. So off on to google I went for an impromptu crash course in emergency plumbing and central heating (the diynot.com forums are great for this sort of thing)
A couple of increasingly cold days later:-
Costs
Wiring in thermostat None as the cabling was already there (although it was replaced a few weeks later - see below)
Adding vent pipe Around £3 for a 22mm speedfit t-piece. The extra length of 22mm copper pipe was found lying around in the loft
New thermocouple £12
Total cost £15
The previous owners were paying around £1400 per year for gas, basically because they were using the system like a very expensive kettle. After just making the changes above our gas usage dropped by nearly two thirds! I have no idea why the previous owners left the system like this for three years especially when the spare part cost so little.
Total saving - around £900 pounds although this was an extreme situation and I take all of our baseline figures from after we did these works
Was it worth it?
Definitely - as we could very well have met our ends in a shower of boiling water!
Before we bought the house I thought I'd been quite clever. I had asked the previous owners to power up the central heating and confirmed that the radiators got warm and left it at that. I wasn't that concerned as the boiler and the associated plumbing was only about 6 years old - what could possibly have gone wrong in that amount of time? Quite a lot was apparently the answer....
The first night we properly used the central heating we got a knock on the door. It was one of the neighbours informing us that there was a stream of steaming hot water shooting out of our loft overflow onto the pavement below! Apparently it had been doing this pretty much every day for the last three years. After a bit of investigation it soon became apparent that :-
1. The wall thermostat wasn't actually wired in, so the boiler would just keep going until the timer switched it off. This in it's self, whilst not terribly efficient, wasn't necessarily dangerous (there are plenty of old boilers that don't have a room stat) however the second issue was.
2. The boilers internal thermostat, which basically turns off the gas burners once the water is hot enough had failed. This meant that the water in the central heating system was just getting hot and hotter and closer and closer to boiling point. A quick poke of my head in the loft indicated that the plastic expansion tank in the loft was full of steaming water and it was starting to melt. The only thing stopping it from reaching total meltdown was the emergency thermal cut out switch on the boiler, however if this had failed then we faced the very real possibility of a tank of boiling water pouring on our heads.
At this point the power to the boiler was switched off and we pondered. Having spent what seemed like the equivalent of a small country's GDP on the house, we didn't have any spare cash to call in a plumber. So off on to google I went for an impromptu crash course in emergency plumbing and central heating (the diynot.com forums are great for this sort of thing)
A couple of increasingly cold days later:-
- The thermostat was correctly wired in and switching off the heating once the room was up to temperature
- I had added a vent pipe to the system - strangely the "plumber" who installed the system had decided that a vented hot water tank didn't seem to need a vent. This is an essential safety feature!
- I had replaced the thermocouple in the boiler so that it didn't over heat anymore.
Costs
Wiring in thermostat None as the cabling was already there (although it was replaced a few weeks later - see below)
Adding vent pipe Around £3 for a 22mm speedfit t-piece. The extra length of 22mm copper pipe was found lying around in the loft
New thermocouple £12
Total cost £15
The previous owners were paying around £1400 per year for gas, basically because they were using the system like a very expensive kettle. After just making the changes above our gas usage dropped by nearly two thirds! I have no idea why the previous owners left the system like this for three years especially when the spare part cost so little.
Total saving - around £900 pounds although this was an extreme situation and I take all of our baseline figures from after we did these works
Was it worth it?
Definitely - as we could very well have met our ends in a shower of boiling water!
Upgrading the heating controls

Wireless thermostat transmitter
Now that the heating wasn't going to kill us, it was time to start optimising it to make it more efficient.
Within a few weeks of living in the house we soon discovered that upstairs was often far too hot and downstairs was freezing.
It didn't take very long to figure out why - the house has an open stairway in the dining room, so much of the warm air tends to head up the stairs. The thermostat was also located on the upstairs landing right where the warm air tended to gather - hence it did not come on even when it was cold downstairs.
We thought about boxing in the stairs and fitting a door at the bottom, however this would really have closed in what was already a fairly small dining room so this option was rejected.
The most obvious solution was to move the existing thermostat downstairs, however this would have involved extending a lot of cabling so wasn't an easy option. I decided that if I was going to go to the trouble of moving the thermostat then I might as well upgrade to a digital model rather than the inaccurate mechanical stat that I currently had.
Whilst researching which digital model to buy I suddenly noticed that a number of wireless thermostats were available - these seemed the answer to my prayers!
A wireless thermostat is made up of two parts:-
After a quick trip down to Screwfix, installing the the new receiver was really simple, and within 15 minutes I had the new wireless stat up and running. With the transmitter unit being so portable, we were able to to try it in various positions downstairs to see which gave the most comfortable temperature. In the end we settled on the unit being at the bottom of the stairs on a wooden column.
This didn't stop the heat slowly floating up stairs - however I soon realised that we already had a means of dealing with this.
Within a few weeks of living in the house we soon discovered that upstairs was often far too hot and downstairs was freezing.
It didn't take very long to figure out why - the house has an open stairway in the dining room, so much of the warm air tends to head up the stairs. The thermostat was also located on the upstairs landing right where the warm air tended to gather - hence it did not come on even when it was cold downstairs.
We thought about boxing in the stairs and fitting a door at the bottom, however this would really have closed in what was already a fairly small dining room so this option was rejected.
The most obvious solution was to move the existing thermostat downstairs, however this would have involved extending a lot of cabling so wasn't an easy option. I decided that if I was going to go to the trouble of moving the thermostat then I might as well upgrade to a digital model rather than the inaccurate mechanical stat that I currently had.
Whilst researching which digital model to buy I suddenly noticed that a number of wireless thermostats were available - these seemed the answer to my prayers!
A wireless thermostat is made up of two parts:-
- A receiver which replaces your existing thermostat - this was ideal as it meant I could use the existing wiring.
- A battery powered transmitter unit which contains the controls and senses the the temperature. This unit could be placed anywhere in the house.
After a quick trip down to Screwfix, installing the the new receiver was really simple, and within 15 minutes I had the new wireless stat up and running. With the transmitter unit being so portable, we were able to to try it in various positions downstairs to see which gave the most comfortable temperature. In the end we settled on the unit being at the bottom of the stairs on a wooden column.
This didn't stop the heat slowly floating up stairs - however I soon realised that we already had a means of dealing with this.
Thermostatic Radiator Valves

One of our TRV's
Thermostatic Radiator Valves (TRV's) are great devices which detect the temperature in the room and shut off the water supply to the radiator once a certain temperature has been reached. This allows you to have certain rooms at lower temperatures that others. They are relatively cheap (from only around £5 from Screwfix) and can be fitted by anyone with some basic plumbing experience. We we lucky enough to already have TRV's fitted on all our radiators - at least the plumber had got something right!
The first step was to set the TRV's upstairs to a lower temperature than those downstairs, and allow the hot air rising through the house to keep the first floor warm. This meant that most of the heating was now being provided to the ground floor radiators and with the thermostat also now being downstairs ensured that were no longer boiling upstairs and freezing in the living room.
The second step was to disable the TRV in the dining room where the thermostat was located. This is important as otherwise the TRV and room thermostat will "fight" each other i.e. if the temperature on the TRV is set lower than the room stat then the temperature in the room may never get up to the temperature set by the thermostat and the heating will run for much longer than necessary.
Disabling the TRV is quite easy - either open it to it's highest setting (assuming this is higher than your thermostat temperature) or just unscrew the TRV head. Consult the manual for your TRV if in any doubt
Costs
Wireless thermostat £50 fitted myself (please consult an electrician if you have any doubts)
Impact - as the heating controls were changed (along with many other parts of the heating system) within within a few weeks of moving in it's impossible to say what cost saving changing the controls had by themselves. However we are now able to have much finer control over heating times and temperatures which allows us to use the heating much more efficiently.
Was it worth it?
The new thermostat and adjusted TRV's have made the house much more comfortable and quick to heat up. For very little relatively outlay we have made a huge impact on the way we live.
The first step was to set the TRV's upstairs to a lower temperature than those downstairs, and allow the hot air rising through the house to keep the first floor warm. This meant that most of the heating was now being provided to the ground floor radiators and with the thermostat also now being downstairs ensured that were no longer boiling upstairs and freezing in the living room.
The second step was to disable the TRV in the dining room where the thermostat was located. This is important as otherwise the TRV and room thermostat will "fight" each other i.e. if the temperature on the TRV is set lower than the room stat then the temperature in the room may never get up to the temperature set by the thermostat and the heating will run for much longer than necessary.
Disabling the TRV is quite easy - either open it to it's highest setting (assuming this is higher than your thermostat temperature) or just unscrew the TRV head. Consult the manual for your TRV if in any doubt
Costs
Wireless thermostat £50 fitted myself (please consult an electrician if you have any doubts)
Impact - as the heating controls were changed (along with many other parts of the heating system) within within a few weeks of moving in it's impossible to say what cost saving changing the controls had by themselves. However we are now able to have much finer control over heating times and temperatures which allows us to use the heating much more efficiently.
Was it worth it?
The new thermostat and adjusted TRV's have made the house much more comfortable and quick to heat up. For very little relatively outlay we have made a huge impact on the way we live.