Are my showers and OSO unvented cylinder plumbed correctly?
Discussion
Hi,
I have a OSO hot water unvented cylinder which is connected to two showers. However, one shower is powerful but has a very tight thermostat, whilst the other has a very weak flow. It barely flows out the end of the shower head!
So, reading through the user manual... http://www.jhplumb.com/system/brand_attachments/68... it says that the showers cold supply should be connected to a balanced cold water feed, not directly to the mains. Connecting it to the mains may result in a tight shower control. This is exactly what I have in the first shower. But why would the second shower have such bad flow? The manual states that the shower cold supply be connected to the T on the PRV.
Here's how the supply to the hot water cylinder looks. You can see the PRV with nothing connected on the T, just a blank. Should the shower cold supplies be connected here? At the moment the cold to the shower is connected straight to the mains supply, before it gets to the hot water cylinder.
Any help will be much appreciated, so I can have a shower control in one bathroom that works and decent flow out the other!!
Thanks,
Dan
I have a OSO hot water unvented cylinder which is connected to two showers. However, one shower is powerful but has a very tight thermostat, whilst the other has a very weak flow. It barely flows out the end of the shower head!
So, reading through the user manual... http://www.jhplumb.com/system/brand_attachments/68... it says that the showers cold supply should be connected to a balanced cold water feed, not directly to the mains. Connecting it to the mains may result in a tight shower control. This is exactly what I have in the first shower. But why would the second shower have such bad flow? The manual states that the shower cold supply be connected to the T on the PRV.
Here's how the supply to the hot water cylinder looks. You can see the PRV with nothing connected on the T, just a blank. Should the shower cold supplies be connected here? At the moment the cold to the shower is connected straight to the mains supply, before it gets to the hot water cylinder.
Any help will be much appreciated, so I can have a shower control in one bathroom that works and decent flow out the other!!
Thanks,
Dan
After the isolation is the combination valve. Sometimes these have an output for a balanced cold, oother times the cold is taken off after the combination valve via a T.
Both supplies are therefore balanced.
You can take the cold off the 'raw' unbalanced main but unbalanced supplies causes issues. You can put a reducing valve on the incoming main, but it's best to rely on one valve as both would alter together if a fault occurred, no discrepancies.
The valves PRV with a flexy is horrid, but maybe it's the OSO way. I also prefer a quarter turn lever valve which is full bore over a traditional stopcock.
You'll have to relate this to yours and see if it makes sense!
Also, there maybe restrictors in the shower, or restrictions in the pipework reducing flow, reduced bore iso valves for example.
Both supplies are therefore balanced.
You can take the cold off the 'raw' unbalanced main but unbalanced supplies causes issues. You can put a reducing valve on the incoming main, but it's best to rely on one valve as both would alter together if a fault occurred, no discrepancies.
The valves PRV with a flexy is horrid, but maybe it's the OSO way. I also prefer a quarter turn lever valve which is full bore over a traditional stopcock.
You'll have to relate this to yours and see if it makes sense!
Also, there maybe restrictors in the shower, or restrictions in the pipework reducing flow, reduced bore iso valves for example.
Gingerbread Man said:
After the isolation is the combination valve. Sometimes these have an output for a balanced cold, oother times the cold is taken off after the combination valve via a T.
Both supplies are therefore balanced.
You can take the cold off the 'raw' unbalanced main but unbalanced supplies causes issues. You can put a reducing valve on the incoming main, but it's best to rely on one valve as both would alter together if a fault occurred, no discrepancies.
The valves PRV with a flexy is horrid, but maybe it's the OSO way. I also prefer a quarter turn lever valve which is full bore over a traditional stopcock.
You'll have to relate this to yours and see if it makes sense!
Also, there maybe restrictors in the shower, or restrictions in the pipework reducing flow, reduced bore iso valves for example.
Thanks for your reply, you seem to be helping me with a lot of my questions lately!Both supplies are therefore balanced.
You can take the cold off the 'raw' unbalanced main but unbalanced supplies causes issues. You can put a reducing valve on the incoming main, but it's best to rely on one valve as both would alter together if a fault occurred, no discrepancies.
The valves PRV with a flexy is horrid, but maybe it's the OSO way. I also prefer a quarter turn lever valve which is full bore over a traditional stopcock.
You'll have to relate this to yours and see if it makes sense!
Also, there maybe restrictors in the shower, or restrictions in the pipework reducing flow, reduced bore iso valves for example.
The only thing after the valve is just the cylinder, so the showers are definitely being fed from the mains. There is another out on the valve, but it's blanked off. Should I change this? One shower would be easy to change, as the pipes are in the cupboard so it would just be a rearrange of pipe work, but the other shower would be a lot more difficult as it's at the other end of the house.
I actually fitted the other shower (the very slow flowing shower). When the house was built it had a bath tap with built in shower hose on the top of it. I installed a proper shower mixer valve on the wall and took a T off the tap pipes to supply the shower. I don't know if the shower I installed has a restricter, how would I find this out?
You could buy a pressure reducing valve and bung it on the cold main after the mains internal stopcock. Balance it up to the 3.5 bar (?) that the cylinder runs at and balance the house.
That would hopefully solve both showers. Or replumb to just fix the one shower you can get at easily. Or try and find the route of the incoming main. Try to connect a balanced cold to one end aka the shower which is also the bath feed, basin feed etc and cap it after the last appliance, and therefore capping the feed from the cold raw main.
As for flow restrictors. Either in the hot inlet and cold inlet or on the outlet to the shower head. Different coloured plastic items about the size of a 5p.
That would hopefully solve both showers. Or replumb to just fix the one shower you can get at easily. Or try and find the route of the incoming main. Try to connect a balanced cold to one end aka the shower which is also the bath feed, basin feed etc and cap it after the last appliance, and therefore capping the feed from the cold raw main.
As for flow restrictors. Either in the hot inlet and cold inlet or on the outlet to the shower head. Different coloured plastic items about the size of a 5p.
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