Yesterday I noticed our stop-tap wasn't fully on, it was at about 60%. So I turned it all the way on, can't go wrong with more water pressure right? The heating came on today and it got much hotter than usual, much faster, and all of the radiators are absolutely scorching to the touch! I assume the increased water pressure is responsible? Perhaps pushing heated water around the system more quickly? My question is this? If the boiler is on for the same amount of time, is it costing us more? Or is the system just more efficient because the waters flowing quicker? Thoughts welcome! We have this combi boiler if it helps: http://interpart.partsarena.eu/System/DATA/Dx/DS1/user/4737/U29-4737/U29-4737.htm#SECT3
Combi boilers are rated at x litres per minute for hot water - the heating system is a closed loop, and the same water just circulates. Low pressure in the loop would result in reduced performance but that should have been evident on the pressure gauge.
Exactly this. The only real change you would see is better pressure from the taps. Even with a condenser its self regulating. One possible explanation could be that you had low pressure to start with and the fill up loop is slightly open and so had topped up the boiler. But in that case I would check the presure is correct and make sure the fill up loop is shut
I would agree that opening the stop tap fully must somehow have caused the fill loop to further fill the boiler --the two are not connected in any other way. However running the boiler under too high pressure is not good. The boiler pressure gauge should tell you what is an acceptable range --normally between 1 and 3 bar. Keep in mind that this goes up as the central heating heats up, so a cold boiler may register 1 bar pressure and a hot one nearly 3 bar. The best way to optimise central heater efficiency is to bleed all the radiators so there are no air pockets in them that prevent them from filling fully with hot water. Start at the bottom, work your way up. Then (and only then) fill the central heating to 1 bar --slowly! Opening the fill loop valve too far too quickly risks breaking the boiler with the sudden increase in water pressure. Close the fill loop valve fully afterwards. Water will be cold at this stage, so let the central heating run and once it has reached temperature (about 60 degrees water temperature), see if you need to top up to about 2 bar. If pressure exceeds 3 bar, just bleed the nearest radiator until water pressure drops within the desired range. Of course always read the manual, which instructions supersede the above.
If you need to drop the pressure there is a red knob usually at the back on the PVR ( pressure release valve). turn it and it will open the valve and release the pressure. It's on a quarter turn spring so a quick tweak than let go and it will shut off on it on in an instant.. You will feel it vibrate slightly and the pressure drops.
