Problem with both showers....

[TheKeymeister]

Hi,

We've got 2 showers, a pumped electric shower (has hot and cold feed) in the en suite, and a mixer tap in the bathroom with shower attachment. Hot water is supplied from a cylinder via open vented Y plan system, there's a cold water storage tank supplying the hot water cylinder and pumped shower only. Bathroom shower's cold feed is from the mains rather than storage tank.

Last night the son was in the pumped shower and came out and said the hot water had run out which I thought was odd. Thought nothing of it and got in this morning, turned it on, and it started coughing and spluttering and was very cold. No problem I thought, so I tried the shower in the bathroom, and it was fine when tuned to the right temperature through the mixer taps, but when you pulled the button for the shower it was very cold and next to no pressure.

Yesterday evening I was putting stuff in the loft, so went up this morning to see if I'd knocked anything or if there was a leak, as the pipework to the shower in the en suite runs along the loft surface (in climaflex), also checked the cold storage tank, the ball valve is dripping a bit but it is filling as it should.

Also yesterday evening, I noticed an Anglian Water van driving about our street (cul de sac) at around 7pm, looking for a house (I've done callout work before so recognise the symptoms!). I did think the cold pressure was slightly higher than usual so tried winding the stop cock in a couple of turns, this has slightly improved things in the bathroom shower, but I can't see how that would affect the ensuite pumped shower.

I am thinking the cold water is drawing into the hot feed through the shower/s, and maybe a couple of check/non-return valves would sort it, but it seems a bit strange that it's all happened suddenly and worked fine yesterday morning. Or is this all just a massive coincidence and I'm over thinking things?

Many thanks in advance

 

[bernardgreen]

Could the mains water have been turned off while your son was in the shower ? ( Anglian Water van in the area to sort out problems it caused ? ).

If the supply to the hot water cylinder was higher in the cold water tank than the cold feed to the shower then as the tank emptied the hot water would cease flowing before the cold water ? ( as it should to prevent scalding ).

Coughing and spluttering would be the pipes clearing out the air that got in when the tank was getting empty.

 

[TheKeymeister]

That would make good sense actually, I was thinking how would it have an affect on the pumped shower as it's fed off the tank but didn't contemplate it could have totally emptied it. Will go and let it run for 5 mins and see what happens.

It's all still a bit new to me, all my previous houses have been in the city with combis with no storage tanks and a reliable water supply!

Have checked the Anglian Water site and it says there was an issue yesterday at the other end of the village and they've dug up the road so that could be the root cause.

 

[TheKeymeister]

All sorted I think! Glad I posted here before cracking the spanners out just for air in the pipes!

As an aside I take it the fill valve on the cold water tank shouldn't be constantly dripping/trickling? The level is a long way off the overflow, looks like it might have been artificially set low so it doesn't overflow though.

 

[Hugh Jaleak]

Pull the ballvalve up gently, see if it shuts off fully. This area is generally known for very hard water, limescale build up will cause ballvalves to fail eventually, if in doubt, for what its worth, I'd change it.

 

[Agile]

Partially closing a stopcock has no effect on pressure at all.

All it does is restrict the FLOW when higher flow rates are taken.

Why do people seem unable to understand the difference between pressure and flow?

Teresa May should be getting the schools to teach people simple everyday physics before completely changing the stablished types of schools.

 

[TheKeymeister]

Pull the ballvalve up gently, see if it shuts off fully. This area is generally known for very hard water, limescale build up will cause ballvalves to fail eventually, if in doubt, for what its worth, I'd change it.

Thanks...I'll have a look. My toilet fill valves were pretty limescaley so that's probably the same after 20 years of it, I'll probably change it after all.

Partially closing a stopcock has no effect on pressure at all.

All it does is restrict the FLOW when higher flow rates are taken.

Why do people seem unable to understand the difference between pressure and flow?

Teresa May should be getting the schools to teach people simple everyday physics before completely changing the stablished types of schools.

It was 6am this morning, I was ****ed off I couldn't have a shower, and started trying simple things to try and make it work, mainly because I'd previously read somewhere online that winding the isolation valve in a bit on my toilet might ease the water hammer (which it did) until I got round to changing the fill valve.

I'm not a plumber, I'm an electrical engineer, posting on a DIY forum, and personally I don't understand why people need to use the 'water analogy' to understand volts, ohms, amps etc - but everyone's different. Funnily enough I was taught about volts, amps, ohms but not about flow and pressure, feel free to take it up with my school, I'd have found it far more useful than English Literature!

 

[bernardgreen]

Teresa May should be getting the schools to teach people simple everyday physics before completely changing the stablished types of schools.

Good idea, but it will be necessary to separate Grammer from Technical other wise there is too much in the curriculum and thus the quality of education has to be dumbed down to fit into avialable teaching time.

I have started a selective eduaction thread in General Discussion.

 

[TheKeymeister]

Just as a conclusion to this, the shower started acting weird again the other day, but permanently this time. Turns out the fill valve in the cold water tank was only giving a trickle, and the shower was often sucking on air, so replaced that.

That gave a slight improvement, but the pump was running at maximum thrust all the time and it wasn't as powerful as before. Changed the gate valve feeding the shower from the cold tank (which was stuck at 90% closed) for a new full bore lever ball valve and all is good again.

 

[Agile]

Well if you have a pot at 90% of maximum resistance you would not expect much current!