Low cold water pressure in the bathroom only

ce5656

I just bought a flat which is in a purpose built block. We spent our first night in the flat last night and I noticed that the cold water pressure everywhere in the bathroom (sink, loo, bidet and shower) is very low. Hot water in the bathroom is normal. I checked the kitchen and both cold and hot water pressure is normal. 

Our hot water and heating bill is included in the service charge so I assume that hot water comes from a different source (there's a communal boiler in the basement). I can't see any pipes other than the ones feeding the sink tap.

Thanks a lot in advance for any advice on this!

Alter_ego

Bathroom cold could be fed from a tank rather than direct from water main.

ce5656

Alter_ego said:

Bathroom cold could be fed from a tank rather than direct from water main.

Thanks for the comment! Sorry if this sounds stupid but what does it mean? Do you mean a cold water tank for the whole building somewhere which may not be working properly? 

Alter_ego

If there is a tank it would be normal for the pressure to be less than mains. Without knowledge of your building it's very hard to be sure how it is piped.

ce5656

Alter_ego said:

If there is a tank it would be normal for the pressure to be less than mains. Without knowledge of your building it's very hard to be sure how it is piped.

Do you think my best bet is to contact the management company first? The shower is so hot I can't imagine anyone feeling comfortable using it...or shall I try to speak to a neighbour first so I know if it's just my flat?

BUFF

I think that I would introduce myself to my new neighbours & slip the questions into the conversation ...

What type of shower (control) is it?

ce5656

BUFF said:

I think that I would introduce myself to my new neighbours & slip the questions into the conversation ...

What type of shower (control) is it?

I'm not very familiar with the terminology but it's like a rectangular metal plate on the wall with two knob switches on it. The one on top is to control water flow and the bottom one is to control temperature. When I turned the bottom switch to the coldest setting, there's very little lukewarm water coming out of it. When I switched it to the hottest setting, it's very powerful but also very hot!

The sink has a mix tap and it's possible to get cold water only but the flow is very small.

FreeBear

Check you stopcock is open fully (less half a turn). It might be in the kitchen and/or next to a water meter (if you have one).

BUFF

ce5656 said:

BUFF said:

I think that I would introduce myself to my new neighbours & slip the questions into the conversation ...

What type of shower (control) is it?

I'm not very familiar with the terminology but it's like a rectangular metal plate on the wall with two knob switches on it. The one on top is to control water flow and the bottom one is to control temperature. When I turned the bottom switch to the coldest setting, there's very little lukewarm water coming out of it. When I switched it to the hottest setting, it's very powerful but also very hot!

Photo?
Hopefully it's a themostatic valve so you should be able to find an intermediate setting.

Bendy_House

The next obvious move would be to contact the building management co. Ask what system they have supplying the H&C.

The KITCHEN cold will definitely be supplied directly from the mains as this is drinking water. The HOT, you say, is supplied via a communal boiler, so this will very likely be pumped or else it could struggle to supply all the flats simultaneously. A communal supply suggests a storage system somewhere, very likely on the roof or a loft space, and then some method of heating the hot water - either a separate hot cylinder, or via a coiled pipe in a thermal store, summat like that. This extra 'hot' part would add more flow resistance, so the installers may have deemed a pump was required.

The bathroom cold will also, most likely, be supplied from a large storage tank, very possibly the same one as for the hot. But, as this supply is a simple direct route to the flats, they might have consider 'gravity' was good enough, and not bothered with a pump for this.

There. Complete speculation. And you've read it all

Your shower is struggling to give a good flow as the pressures are imbalanced - the hot overwhelms. 

No harm in also having a chat with your neighbs, ideally one on the same floor level.

The fix will depend on the cause. Last resort could be to add a gentle water booster to the cold in that bathroom.

Just HOW poor is the cold flow, with bath tap full on? And the hot?

ce5656

Bendy_House said:

The next obvious move would be to contact the building management co. Ask what system they have supplying the H&C.

The KITCHEN cold will definitely be supplied directly from the mains as this is drinking water. The HOT, you say, is supplied via a communal boiler, so this will very likely be pumped or else it could struggle to supply all the flats simultaneously. A communal supply suggests a storage system somewhere, very likely on the roof or a loft space, and then some method of heating the hot water - either a separate hot cylinder, or via a coiled pipe in a thermal store, summat like that. This extra 'hot' part would add more flow resistance, so the installers may have deemed a pump was required.

The bathroom cold will also, most likely, be supplied from a large storage tank, very possibly the same one as for the hot. But, as this supply is a simple direct route to the flats, they might have consider 'gravity' was good enough, and not bothered with a pump for this.

There. Complete speculation. And you've read it all

Your shower is struggling to give a good flow as the pressures are imbalanced - the hot overwhelms. 

No harm in also having a chat with your neighbs, ideally one on the same floor level.

The fix will depend on the cause. Last resort could be to add a gentle water booster to the cold in that bathroom.

Just HOW poor is the cold flow, with bath tap full on? And the hot?

Hi, thank you for the comment! Sorry I only came back to check my post a few days later.

The shower has a good pressure (of very hot water) when I switch it to the hottest setting. The more I turn it to the cold side, the weaker the flow becomes. At its coldest setting, there's barely any water coming out of the shower head.

But the basin and the bidet do have a small cold only flow, maybe the thickness of a pencil. If I then turn the tap a little bit to the hot side, the mixed hot and cold flow is comfortable and strong enough to wash my hands. For the basin tap, at its hottest side the flow is too strong to wash my hands without water splashing everywhere (and of course it's also too hot to use).