Closed central heating system with open tank

[ultrasonic]

So basically this is my parents house. When a new bathroom was fitted approx 8 years ago the open vented system was converted to a closed presurised system or so I thought! The airing cupboard hot water tank was scrapped and a new cylinder fitted in the loft as you can see in the pics. The hot water pressure has always been poor since.

What I'm looking at in the loft is a header tank but surely it shouldn't be there in a closed system!? When a toilet flushed I observed some water pumping through the curved pipe into the tank as the cistern shut off. The feed to this tank comes up through the floor of the loft. At the moment the tank is full but the other week it was almost empty. What's your take on this setup? The cylinder pressure relief pipe goes outside so it's not that.

 

[CBW]

Looks like they’ve only pressurised the hot water. That cistern looks like it’s being used for the central heating, but shouldn’t be empty unless you’ve got a leak somewhere. If the cold main is poor, the hot water delivery will be too, especially the further up it’s got to go.

Any idea what the cold main pressure is and flow rate?

 

[ultrasonic]

Looks like they’ve only pressurised the hot water. That cistern looks like it’s being used for the central heating, but shouldn’t be empty unless you’ve got a leak somewhere. If the cold main is poor, the hot water delivery will be too, especially the further up it’s got to go.

Any idea what the cold main pressure is and flow rate?

The cold pressure supply in the street is quite poor. Yorkshire water replaced the pipes in the street recently along with new valves but it's not really helped. I don't have a gauge to read the bar.

 

[CBW]

Then your hot water cylinder is probably in the wrong place, and possibly mis-sold. I’m not sure fair with certain types of system, but you may have been better with an accumulator?

 

[SandyLyon]

On a separate note, there’s a distinct lack of pipe / tank insulation up there.

 

[ultrasonic]

On a separate note, there’s a distinct lack of pipe / tank insulation up there.

Yes, you're right. I'll get some bought this week.

 

[Exedon]

That's not the best heating feed tank not enough hight above circulating head. Should really have been sealed system
The 15mm cold supply to cylinder if you have poor pressure and or volume was never going to work correctly.
Workmanship to be blunt poor.

 

[ultrasonic]

That's not the best heating feed tank not enough hight above circulating head. Should really have been sealed system
The 15mm cold supply to cylinder if you have poor pressure and or volume was never going to work correctly.
Workmanship to be blunt poor.

Given the poor mains pressure, if the heating system was pressurised and we got rid of the header tank would the radiators heat up quicker? Even a brand new rad is taking 20+ minutes to get hot.

Unfortunately don't think much can be done about the 15mm supply to the cylinder without major work.

 

[Hugh Jaleak]

Given the poor mains pressure, if the heating system was pressurised and we got rid of the header tank would the radiators heat up quicker? Even a brand new rad is taking 20+ minutes to get hot.

Short answer to that is No. Further investigation would be required to see if there is an issue with the CH system.