Curious about potential reasons for drop in shower pressure.

[dpm_dpmartin]

Hello,

My first post here and I think it worth pointing out that I am a layman in these terms - just a normal home owner. I'd be very interested if anyone had any advice to offer.

I have had an Aqualisa Axis Digital shower for a year or so now, it is fed by my combi boiler and no pump is involved. The Aqualisa Axis range has this remote processor (basically a mixer of hot and cold I believe) that is situated some way from the shower head.

When I first got the shower it nearly knocked me over - it was that good. And I was most impressed and pleased, considering it cost me around £700 and even more for getting it fitted by an Aqualisa approved installer - good guys these were though.

I have experienced a number of separate incidents where the pressure has dropped off - sometimes to where the water is just falling out - as opposed to being shot out at me.

The first time, I got in touch with Aqualisa technical services and they advised me to check there wasn't air in the hose etc., and eventually they sent out an engineer who swapped over the shower head and, miraculously the power came back (almost as good as when it was installed I thought).

The second time I noticed a major drop in pressure Aqualisa advised my combi boiler got checked. I had to pay £100 to get someone to come out and tell me that my boiler was fine. And, eventually, Aqualisa sent out another engineer, who replaced the hose and the shower head and power seemed to come back again - maybe not as good as just after installation, but better. I wasn't happy with spending £100 to find this out, so Aqualisa and I agreed to extend my warranty to 2012 - not a bad compromise.

The most recent time the power dropped off, I engaged Aqualisa technical again - they, surprisingly, told me: "We have recently identified a fault on a small number of the axis handsets causing the rubber spray plate to deform & restrict the flow, the fault has now been rectified." and they agreed that they'd send me a new shower head out (without the identified fault) and I eagerly fitted it - alas, the power has not improved.

This was a disappointment to be honest. I can't blame Aqualisa folk as I do believe they're trying to be helpful and they've changed three shower heads on this thing already. However, I am starting to wonder what else could be wrong here...

This is the crux of my question... what should I be looking for next to get my power back? Any bright ideas welcomed... I can provide all the following information, if of any use...

1) My combi boiler says that it has a pressure of around 1.3 bar, I can increase this if necessary by fiddling with the stuff on it, as per the manual.

2) Could the Aqualisa processor be at fault? It is something anyone has heard of?

3) I had a dishwasher added to my kitchen about a year ago (some time after the Aqualisa shower and the first drop in power which was due to the shower head) - could that affect my entire plumbing system? I mean, does adding more 'devices' to the 'system' drop the load 'pressure' across the whole thing, or is that not a good analogy at all in plumbing?

4) Could I have fallen foul of some house-wide drop in pressure from the water company? Or is that not even relevant to my issue as my shower is being fed by my combi boiler and it's all related to what that can spit out?

Apologies for the naive questions. It's a real shame that this is happening... but I'd just love to know how I can get back that amazing pressure I had recently after installation. I'm willing to investigate the boiler, the processor, the shower - whatever - so, please, do provide any information you might have or ask any questions you might wish to for clarity... many thanks.

Cheers, DpM
http://www.hmusiccentre.org.uk

 

[gas4you]

Have you noticed any reduction in flow from any other hot taps in your house, or even cold taps?

Do you live in a hard water area?

What make and model of combi do you have?

 

[dpm_dpmartin]

Thanks for the response... here are the answers:

1) I have not noticed any reduction in flow from taps; although it is also something I've not paid close attention to in the past, I will admit that. All I've noticed is the shower because it is so obvious.

2) I am in south Sheffield and from the map I see at the following URL http://www.dwi.gov.uk/pubs/hardness/index.htm#4 I guess I am in a "slightly hard to moderately hard" or "hard to very hard" area if I've placed myself correctly. It's not "soft to moderately soft" any way.

3) It is a Saunier Duval, Themaclassic F24E PLUS Fanned Flue Combination Boiler, G.C. No. 47-920-37... the specs. table from the manual says stuff like:

Heat input (max) = 25.9kW, 88.370 BTU/H
Heat input (min) = 12.3 kW, 41.967 BTU/H
Efficiency = 78.3%
Maximum heating temp. = 87C
Maximum hot water temp. = 65C
Expansion vessel effective capacity = 6.5 litres
Expansion vessel charge pressure = 0.5 litres
Maximum system capacity at 75C = 125 litres
Specific flow rate (for 30C temp rise) = 11,3 litres/min.
Threshold flow rate = 1.7 litres/min.
Maximum supply pressure = 10 bar
Minimum supply pressure = 0.5 bar

...I just checked it and it tells me it is currently sitting at 1.7 bar.

I have never been happy with this boiler, but it's what I'm stuck with. It is around 3 years old - a Hepworth Heating Engineer (Belper, Derbyshire) has checked it in the last year - but they were basically confirming (in their eyes) that it wasn't the cause of my shower losing pressure - and that cost me £100.

Cheers, DpM
http://www.hmusiccentre.org.uk

 

[Slugbabydotcom]

1 CH system pressure has nothing to do with the water that comes from your shower.

2. Never seen your shower so I can't comment on that.

3 Only if these other devices are drawing water at the same time as your shower

4Perhaps although its more likely that someone has turned the water off and not reopened the stoptap properly

Other stuff
You could be at the start of a long road here. An experienced plumber should be able to home in on the fault rather quickly.
Heres some suggestions.

Its winter! Your boiler has more work to do. The mains water temp is colder. Your valve can only mix in the amount of hot water it is given.
The boiler could be struggling just because its winter or perhaps another reason eg. the gas pipe is undersized or the burner pressures aren't set up properly or theres another fault such as a sensor.

There could be a blockage in the water supply perhaps because of a blocked filter or slightly [instead of fully] open valve anywhere along the line from the pumping station through the mains into your house up to and beyond your boiler into and the shower and again including the shower head.
Testing pressure and water flow rates at various points is the only way to get to the bottom of that one.

 

[dpm_dpmartin]

Slugbabydotcom, thanks.

1) Fair enough, that makes sense to me.

2) Understood - could be shower (different parts), but could not be.

3) Again, that makes sense to me; so no issues with adding dishwasher.

4) Water will have been turned off when dishwasher was added, I am sure. Now, if the drop in shower pressure occurred at the same time, it could be 'cos someone turned the water off and didn't open the stoptap (this is the stopcock, yes?) fully.

I will check into number 4 and see what I can see.

Although I've just added this entry to the forum, that's mainly because I've just found the forum. I've noticed the drop-off in shower pressure for some time and not just as it was getting colder. I had observed it for some time before getting in touch with Aqualisa. So my conclusion here is that should not be winter related.

Are there any facts and figures about what flow rate someone is supposed to get from the mains? I guess it would just be cold you could assess 'cos hot is, again, dependant on what your in-house equipment can provide... or am I barking up a wrong tree there? Do I ask questions of my water supplier, or is that not a route really available to me?

Opening up many avenues here is probably not my best bet. I'm trying to isolate things that have changed and have, thus far, only come up with the addition of a dishwasher, which we agree really shouldn't cause this; that is one piece of good news I guess.

Cheers, DpM
http://www.hmusiccentre.org.uk

 

[dpm_dpmartin]

Done. Apols..

 

[Ali88]

Done. Apols..

Hi. I am having a similar problem with my Aqalisa Quartz shower. The water pressure keeps dropping and usually only resets itself if a light bulb blows or I put the trip swiych down on the electricity! This time however, the electricity trick isn't working and I have really bad pressure.

I know your post was some time ago but I was wondering whether you managed to resolve the problem and if so how? If you wouldn't mind is there any way you can email me at [email protected]. Many thanks!