Gledhill Envirofoam Hot Water Cylinder Power Shower Tapping

[old wrinkly]

I have recently had a Gledhill Envirofoam Stainless Steel SE 42x16 IND Hot Water Water Cylinder (HWC) installed to replace an aging copper cylinder.

With the copper cylinder I had a Surrey Flange, one outlet of which served my main use kitchen-bathroom and the other went across to my extension and served the en-suite with hot water to the sink-bidet and Aqualisa Quartz power shower. This system worked perfectly.

The new HWC has two outlet tappings, one on the top which is being used to provide hot water to my main building and a power shower tapping on the side which as the cylinder has a dip pipe attached to the shower tapping to stop air transferring to the shower and serves the en-suite.

The outlet at the top is always hot but the side tapping is only warm and doesn't even get as hot when water is drawn off in the en-suite, using either the taps or the power shower.

Heating for the HWC is being provided by a 27 inch immersion heater on the top until we switch our oil boiler back on again. Previously we had always heated with oil except in an emergency so this is the only difference.

We are now finding that beside the difference in temperature between the two tappings which is strange, if we run 2 showers in the en-suite within a short time of each other e.g an hour, then although the second shower starts off hot is gradually gets colder.

Gledhill have suggested the problem may be back feed from the cold tank possibly from a blending valve that is pushing back to the pump causing temperature fluctuation but I can't believe this is the case because everything was fine before fitting the new HWC and it would have to be a major coincidence for it to start playing up just at the same time as the new HWC.

Anyone got any clues as to what might be happening?

FOOTNOTE

My granddaughter has just run a shower and again the water started to run cold. I'd had my shave and no problem and no other shower run this morning. Just checked shower tapping and it's cool. My energy meter shows the immersion heater running.Beginning to think there is a problem with the tank (perhaps the power shower tapping) itself because running hot from the tap in en-suite was also cool although kitchen tap (served from top tapping) hot so clearly nothing to do with power shower?

 

[stardanny]

need to know more about your system:

is the shower cold feed coming from cold main or tank fed?

are you sure the imm heater is 27 inch and not 14 inch? is it new? it should heat about 4/5 of the tank.

has the shower feed pipes fitted with checkvalve?

where about is the side outlet on the tank? 1/3 or 1/2?

possible is that the dip pipe has been moved and now facing down...?

Be aware that the power shower will use up hot water very quick, about 15min to 20min x 2 shower, hot water will run out, less if side outlet.

Dan.

 

[old wrinkly]

Hi

Shower cold feed from tank

Yes, immersion is 27 inch and fitted new with tank

Can't answer question as to whether shower feed pipes are fitted with checkvalves.

Shower tapping (side outlet) is about 9 inches (228mm) from top of tank.

Can't answer if dip pipe is facing down but as tank new must assume not.

Appreciate power shower will use hot water quickly and having 2 showers immediately after each other, before the immersion has had the chance to re-heat the water would be a problem but this was not the case this morning and generally there has been about 30 minutes between showers so water should have been reheated.

Spoke to Gledhill again and they are completely baffled. They agree that the shower tapping and top outlet pipes should be more or less the same temperature. When I was speaking to them I ran the shower for a few minutes which was running hot (the Aqualisa had stopped flashing) but the shower tapping pipe was still only warm and I could keep my hand on it but the top outlet was too hot to keep my hand on.

It's this more than anything else that is baffling because Gledhill state that the shower tapping takes water from the hottest part of the tank i.e the top.

Gledhill did offer to exchange tank but pointed out the same problem might exist and besides which this would involve a further bill from my plumber.

Not tried the new tank with my oil boiler to see if that makes any difference although I can't see why. Also have to say this is the first time we have used immersion for hot water on a regular basis.

 

[picasso]

What is the stat set at on the immersion heater ? the dip pipe would have been installed by your plumber and its quite possible its facing down, get your plumber to check it out, there is usually a mark on the pipe to show which way its orientated.

 

[muggles]

What is the stat set at on the immersion heater ? the dip pipe would have been installed by your plumber and its quite possible its facing down, get your plumber to check it out, there is usually a mark on the pipe to show which way its orientated.

They're pre-formed as part of the cylinder on the Envirofoams, you can't rotate them without ripping the side out of the cylinder.

OP, sounds to me like your cylinder simply isn't heating up sufficiently, maybe because you're not giving it enough time. It'll take far longer to heat up with an immersion than with your oil boiler heating it, and it'll be more expensive too. Try heating the cylinder with your boiler and see what happens then.

 

[old wrinkly]

As stated the dip pipe is pre-installed.

The immersion is permanently on so, as with yesterday morning, having just run a small amount of for a shave, there should have been more or less a full tank of water.

As for costs,with a litre oil producing 3 Kwh of heat at a cost of about 58.0p per litre plus VAT and with electricity at around 8.8p per Kwh it is a better option for the summer at least. This was the general consensus of a number of forums, including DIY that I researched prior to having the hot water cylinder installed.

 

[old wrinkly]

Had a discussion with a friend, not a techie, and we wondered if the problem could be because the immersion stat is turning off the immersion heater before it's been able to heat sufficient hot water.

Had a problem. posted elsewhere on the form, where the new stat would keep tripping out so have adjusted setting to 45C although a rough check with a jam thermometer under the kitchen tap that shows the water is around 60C.

Was thinking of taking the stat out of the loop and running the immersion manually (keeping a close check) to see if the power shower tapping gets any hotter over time.

Also, with my cylinder, how far down would the 27 inch immersion heat. Just took of the normal cylinder stat used when running off the boiler and the tank that far down is cold.

 

[sam8364]

I know this is an old post - but I have essentially the same problem with the same make of tank - although my water is heated by a gas boiler.

The new shower draws of the second outlet on the side of the tank. After one short shower we continue to get piping hot water out of the top of the tank (i.e. to the taps) but cold water through the shower.

I have had a hot tap and shower running simultaneously to test and the water is too hot to touch in the hot tap but running cold to the shower - you can feel this too in the outlet pipes from the tank.

The only thing I can think of is that the draw to the shower must take from much lower down the tank that the outlet at the top!?

Do you think caping the side outlet back off and using a Surrey flange would stop this?

Incidentally I have recently moved house and had the exact same pump and shower installed at the last house with a Surrey flange in a old copper cylinder and we had hot water for two showers no problem.

 

[Nige F]

Do you think caping the side outlet back off and using a Surrey flange would stop this?

.

Probably - yes.

 

[arbitrary]

old wrinkly and sam8364 - did either of you ever get this resolved?

 

[old wrinkly]

Hi, my that's an old thread.

In my case I never quite it resolved. I have stopped using the immersion other than for emergencies as I have had a new condensing boiler installed and I am running that for hot water all the time.

As this is such an old thread I am going to unsubscribe so will not respond to any further messages.