Central heating misery (or mystery)!!

Joined
4 Mar 2020
Messages
4
Reaction score
0
Country
United Kingdom
Hi hope somebody can help! We've had our open system boiler upgraded to a Viessmann Vitodens 050 combi back in August last year. When we had the heating on the first time in November when the thermostat was set to 20℃. After giving birth and having parents coming from the far east to help out, we needed a warm house, and everything was fine and dandy.
However the nightmare started when my parents left and we turned the thermostat down to 18℃ and the system was allowed to cool between fire ups, and we've had to top the pressure up twice a day!
We've had a local heating engineer checked all the radiators and valves and they weren't leaking. The company that installed the boiler checked the boiler and it isn't leaking. So we isolated the boiler and it wasn't the boiler, the pressure dropped from 1 to 0.2 bar when we opened the CH valves back up.
The only time we seem to have a drop in pressure is when the CH is cooling or cold, because I've literally topped up the pressure and had the heating on for 5 hours and no drop in pressure. And there are no damp patches on the ceiling anywhere. Any ideas?
 
Sponsored Links
Joined
28 Oct 2005
Messages
13,658
Reaction score
3,266
Location
Daventry
Country
United Kingdom
Do you have any pipework under the floors downstairs? That would be a good place to start
 
Joined
4 Mar 2020
Messages
4
Reaction score
0
Country
United Kingdom
Do you have any pipework under the floors downstairs? That would be a good place to start
That's what the installer and heating engineer both think, just the hassle I suppose!
But what I don't understand is why is the pressure dropping when it's cold and not when it's hot??? Surely if I have a leak it'll leak even when it's hot???
 
Sponsored Links
Joined
5 May 2004
Messages
435
Reaction score
24
Country
United Kingdom
Pressure whilst hot and running should be approx 2 bar, then dropping to approx 1 bar when cold. What are you seeing that is different ?
 
Joined
4 Mar 2020
Messages
4
Reaction score
0
Country
United Kingdom
Pressure whilst hot and running should be approx 2 bar, then dropping to approx 1 bar when cold. What are you seeing that is different ?

The pressure doesn't rise more than 0.2 bar when it's hot, and when it's at 1 bar it can stay like that for a very long time until suddenly it'll just start dropping at 0.2 bar per hour usually middle of night or early morning
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Top