Low Hot Water Pressure

[AllLectric]

Live in an maisonette (all electric heating and water etc. The hot water tank is upstairs, an Albion Direct Combination Tank with (x2) 3kw heating elements on the side, one above the other.

Have always had bad hot water pressure, so much that with the bath filling the hot water soon slows to nothing with gurgling and other noises.

On the tank low down is a release valve (i assume) if so would could i open this to bleed ?

Or is it somewhere else i should be looking to bleed.

All pipe valve taps are open so greatest water presuure can pass through.

I would prefer to like to do any repair when the water in the tank is cold. Cold rather risk of scalding hot water, or i could heat at a lower temprature, by adjusting the heating element rod temprature adjusters.

 

[seco services]

Have always had bad hot water pressure, so much that with the bath filling the hot water soon slows to nothing with gurgling and other noises.

if running the bath it gurgles and then the water flow stops sounds like the cylinder is emptying quicker than it fills.

check the float valve in the top is opening fully or operating properly.

 

[AllLectric]

Sorry i forgot about that part.

Had the heating elements replaced. Had the float checked was in good working order. Also he adjusted the float valve inlet to increase the cold water inlet pressure, which didn't increase any.

 

[seco services]

check next time you have a bath and the water stops see if the tank is empty or very low.

 

[AllLectric]

Lets assume it is, because when the bath hot water stops to nothing. I hear the cold water filling the tank for about 5-10 minutes. Then after that has finished i can continue to put more water in the bath.

Three to four times then i have anough bath water. To rinse down after i have a bath i find the water has gone cold tepid or cold, where it would have been warm or hot just 30-45 minutes before getting in the bath.

Now we asume that is the problem what would the fix be ?

 

[steved101]

the combi tanks/hw cylinder are usually low pressure.

the float valve is operating OK and the correct size orifice is being used (as you said the plumber checked for)

 

[steved101]

i'd say you have a small h/w cylinder (not big enough) or there is a blockage in the cold feed to the h/w part of the cylinder... hence the slow filling

 

[AllLectric]

This maisonette is in a block with other such maisonettes. We all have direct mains cold water and the cold water pressure is very stong (good). But other massonettes i have visited asked about in the block do not have this hot water pressure problem.

 

[seco services]

if you say the hw cylinder is upstairs wheres the bathroom ?

 

[steved101]

you can't have mains pressure to your h/w though (that would be unvented)!

how big is your hw cylinder?

 

[AllLectric]

if you say the hw cylinder is upstairs wheres the bathroom ?

Bathroom downstairs water cylinder upstairs. 15ft in height from the base of cylinder tank to the bath pipes. Also upstirs is a kitchen (maisonette) low hot water pressure on that tap also, never run it long enough for it to slow or stop. But takes a good 5 minutes to fill kitchen sink to get the bottom of the water escape overfow.

 

[steved101]

Just a poor/low pressure setup that is all - how big is your hot water cylinder though??

 

[AllLectric]

you can't have mains pressure to your h/w though (that would be unvented)!

how big is your hw cylinder?

What i meant is cold water is fed rom the mains. A closet on the block landing has all the main inlet cold water pipes with meters on them for each maisonette. I assume this is direct mains cold water.

Cylinder Size:
1050 x 450 mm

 

[steved101]

no, if there is a float valve (feeding a cold water tank, which sits on top of the hot water cylinder, this is not mains, it is an indirect system).

 

[AllLectric]

Ok thats sounds about right, because when the toilet flushed it feeds cold water into the same tank.

So how can the hot water pressure be improved, corrected to work as normal ?