Not happy with with new unvented system, although it works fine. Shower pressure issue

[kash]

Old setup.
Vented system - indirect
x2 Cold water tank in the loft. x2 80L Hot water tanks, regular boiler and stuart turner 4bar twin shower pump for the master bedroom shower. Worked pretty good, although the tanks were manky and old. The shower though was epic and used to blast water out. The house was gutted for refurbishment so plumber advised to change the set up for a new unvented system, that would deliver mains water pressure throughout the house. which it does.

New set up
Kingspan 300L horizontal tank. No shower pump and just the regular boiler. It’s all installed correctly, signed off and actually works quite well. All the taps and showers get mains water pressure.

Problem
I got too used to the shower pump pressure. The showerhead we have is an XL rainwater shower head and used to love the water blasting out. Whilst the showers still ok, it's just ok and not amazing anymore. If the shower in the family bathroom is run, there's a slight drop in pressure which i was expecting, but this makes the shower experience even less enjoyable.

Is there a solution?
We can’t install the same shower pump on the mains as it would draw too much water from the rest of the house and stop the other taps working - and probably mess with neighbours too. Assume this would also stop things like toilets refilling and draw air once water supply is exhausted.

So my questions are..... What is the solution for me to have a dedicated water supply for the shower again, so that I can use the pump?
Can I install a smaller vented system in addition to the unvented system that I have? The plumbers going to have a think on the best way of achieving this and let me know a price, but thought I’d ask on here too.

I know it’s potentially an expensive addition... but it just depends on cost. The shower is absolutely ok as it is, but i know how good it was and just wanted to make it awesome again.

Are there any other solutions that can be used with the new unvented tank I have?

 

[kash]

Warning Long Long Post

Not for for purpose / design spec eg doesn’t meet minimum spec for unvented manufacturers instructions will list these / g3 also

Shower pumps aren’t rated for constant use you will see listed on them 5/25 or they will say 5 mins use 25 mins rest / cool down etc

As for pressure would be either control group spec eg 3.5 bar or what ever you set the pump at if lower

rated for constant use and suitable for the design spec

sorry don’t understand how it’s more as you still need to get the pipe work two and from the tanks etc

they should have about the same pipe work supply side eg from the tanks

also if your shower pump are positive pressure models and not universal/ negative I’m doubtful there will be enough head pressure to activate them

Bypass the softener and find out or measure the flow before but remember you will need a minimum of 25lpm for an unvented some manufacturers recommend no lower than 20lpm but I believe g3 regs are 25lpm and 3.5 bar

if there not well he’s not done his job hence the problems with not much flow when more than one outlet is used he should of warned you in the beginning you might need x to bring it up to your desired requirements

Yes everything that’s on the install now would get removed except the cylinder eg expansion vessels control group etc

No wouldn’t need inspections / servicing yearly but I wouldn’t count on warranty being valid either as your not using the cylinder as it’s designed for eg mains pressure

also just going back to the pump (shower) there’s no delicate shower pump feed on them so you could start running with dirty water eg air mixed

as for moving the tank to the same room as the cylinder this isn’t going to be good unless you have Universal/neg pumps as there isn’t enough head

you would need a min of 7-8m from the bottom of the tank to the pump for positive

Once again, thank you for your response.

The good news is, that he has agreed Install as per your proposed solution.

I have ordered the Grundfos scala2 pump too. I hope it is a decent pump and have gone on your recommendation alone.

He isn’t going to charge me more than he has already quoted (£700), but I did have to buy the new pump myself at circa £400

As for the tanks, I think we are still proposing to put them in the same loft space if possible to make install easier. Will this still be an issue when using the Grundfos scale 2 pump? Or should I push for these to go into the 2nd floor loft?

When I get the measurements requested- I will call him out on this as I’m fairly certain it’s less than the requirements you stated. Obviously as a consumer, I wasn’t to know this. I just read that it was better all round but there wasn’t too much talk or the required required flows and pressures when doing high level research.

He told me the pressure and flow that I have would be ok for most people so I went with it. If I had known; we wouldn’t be in this position now: but lesson learned.

So all in all- it’s circa another £1100 to sort the problem, but the vented system will be maintained and used in its intended manner.

I’m hoping to recover a little cash by selling the existing pumps on eBay. Infact, the Stuart turner one which retails at £388 on plumbnation already has a bid for £75 - and it still has 2 years warranty left (if anyone’s interested, let me know)

 

[ShaunCorbs]

Good to hear

You can fit them to your spec aslong as the pump isn’t above the tanks

It will be listed in the manufacturers instructions if you have them for the unvented cylinder

as for pump at 3.5 bar your looking around 40lpm output from the pump

my set up will need all the unvented stuff to stay as I’m sure you already understand

let us know how you get on / anymore questions etc

 

[kash]

Good to hear

You can fit them to your spec aslong as the pump isn’t above the tanks

It will be listed in the manufacturers instructions if you have them for the unvented cylinder

as for pump at 3.5 bar your looking around 40lpm output from the pump

my set up will need all the unvented stuff to stay as I’m sure you already understand

let us know how you get on / anymore questions etc

Thanks.

No the pump will certainly not be above the tanks (although I’ve just seen the manual and it seems it has a well suction mode - not that it matters in this case). It will be on the same level or below the tanks. Those figures sound promising for the shower.

On a side note: I also just opened every cold tap in the house (not including any showers) and found that the tap outlet furtherst away wouldn’t even output any supply when all the others were open.

As I closed other outlets, supply gradually came back as expected. The main kitchen tap remained acceptable throughout, but it would as it’s is the 1st outlet in the chain.

The input from you and everyone else has been invaluable so far- and a reason why I love forums (that give sensible responses).

I will certain provide updates as and when. I just hope that it all goes to plan and should be a fairly simple install going forwards.

 

[gpbeck]

At the tap with no flow the pressure would be zero (or worse!) so I hope that is upstairs. If its 5 m above kitchen tap you can be sure the dynamic pressure is less than 0.5Bar at the kitchen tap.

What is the flow from kitchen tap only, with softener, and with softener bypassed? All you need is a bucket and a timer to measure this now and it is VITAL information. Maybe a new mains supply pipe wouldn't cost much more than your plans if you can dig a trench.

 

[kash]

Update

So he came and did the work. I asked him to take measurements and we saw the below. I didn't take all the ones requested as he wasnt intirely in mood to faf about, and not sure how much difference it would have made given that he was on site to do the job anyway.

Direct from mains
Flow rate: 24L per min
Pressure: 2.4 bar
Flow rate AFTER the water softner: 14L per min
Mains incoming pipe: 15mm > this extended into loft space then converted into 22mm into the unvented tank

So it seems that the water softner (water2buy W2B200) was responsbile for a lot of flow / pressure loss. After testing and discussing, it was case of either removing the water softner and wasting £350 + the labour i paid to fit and gain better flow; but still not the amazing shower pressure that I was used to, and still have potential issues when mutiple outlets open, or, go ahead and install the tank and pump anyway and elminate any issues pre-emptivley.

I opted for the later, as this way, i'd have a 300L store of softened hot AND cold water and wouldnt have to worry about loss of pressure with multiple outlets open. It was an expensive solution / addition, but I think i'm happy with it. I need to actually use everything properly in the real world, but from what I played with for about 5 minutes, It seemed like I had both showers pumped (awesome pressure), and every outlet open with decent flow (i'll confirm this again when I have more time to go around and open everything and flush all the toilets at once. Had I never had the water softener installed, i do question If I would have just settled with the output but.... it is what it is and its done now.

I notice that I hear the pump run for a minute or two each time the hot outlet was open (I think as it was refilling the hot unvented tank), but the pump is pretty quiet and it seems like a small price to pay for the solution. Obviously I expect the pump to run for longer when showering, but again, its pretty damn quiet so it's not so bad.

Here's a few pics of the install. He ran out of 15mm pipe lagging but i'm picking some up after work and i'll do this myself as its a 10 minute job. I've got Kingspan coming in to inspect the unvented tank install still on Friday to validate the warranty - so i'm hoping everything is ok and that the set up I now have is up to scratch.

1 thing he did moan about was that online or in the manual i think it said that it was a 3/4 inch fitting but it was actually a 1inch fitting (or the other way around - not sure) - so he had to make up an adaptor.

Thanks again @ShaunCorbs

I'll let you know how things go.

Happy to hear any comments, questions or feedback from what you can see in the pictures.
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At the tap with no flow the pressure would be zero (or worse!) so I hope that is upstairs. If its 5 m above kitchen tap you can be sure the dynamic pressure is less than 0.5Bar at the kitchen tap.

What is the flow from kitchen tap only, with softener, and with softener bypassed? All you need is a bucket and a timer to measure this now and it is VITAL information. Maybe a new mains supply pipe wouldn't cost much more than your plans if you can dig a trench.

Digging a trench wasnt an option unfortanatly.

 

[ShaunCorbs]

Water softeners for your home | Culligan Harvey

www.harveywatersofteners.co.uk

High flow rate up to 55lpm

 

[kash]

Water softeners for your home | Culligan Harvey

www.harveywatersofteners.co.uk

High flow rate up to 55lpm

Sorry - not sure what you mean?

 

[SJB060685]

Sorry - not sure what you mean?

I assume hes posted a link to a water softener that provides better flow rates than your existing

 

[ShaunCorbs]

Sorry - not sure what you mean?

I’m recommending harvys if you do change your water softener later on

 

[EvilDrPorkChop]

That plumbing certainly looks interesting......glad it all works!

But from what you've said your flow rates entering the house are fine. If it had been fitted with a 22mm main up to the cylinder and a better softener then i'm sure you wouldn't have had any issues with the standard set up.

 

[Scott_D]

does the plumber know about this thread?

 

[gmartine]

Blimey, didn't anybody suggest changing the shower head?

 

[kash]

I assume hes posted a link to a water softener that provides better flow rates than your existing

Ah I missed that, as i was looking quickly on my phone.

I’m recommending harvys if you do change your water softener later on

I did actually have a quote from them - but it was over £800 for their system. However, I never new about or considered the flow rate problems. I assume it was whatever went in, is what came out. The water2buy one didn't mention anything about this on the product page or in the spec's as far as I am aware. Also, I purchased the kit in september so its way past its return period. Not that I need to now, but I will defo look at this factor for a future unit when required.

That plumbing certainly looks interesting....glad it all works!

But from what you've said your flow rates entering the house are fine. If it had been fitted with a 22mm main up to the cylinder and a better softener then i'm sure you wouldn't have had any issues with the standard set up.

Haha - interesting in a good or bad way? In the plumbers defence, we was working in a pretty restricted area with hardly any head room so running the pipework couldn't have been easy for anyone. I agree with your statement about the pipe size and softener though. Thus said, it was too late to do any of that, and digging up the road and driveway at this stage wasn't an option, or was it before. I now know for next time. Lesson learned the hard way i guess. But hey, at least i now have the output that I wanted (thanks to you all tbh, especially shaun).

does the plumber know about this thread?

He knows i've been researching online - but not this particular thread. I am disappointed that he didn't propose these solutions himself, or warn me of the possible issues before we had everything installed. It seems to have been a case of 'curing' issue rather then preventing them.

Whilst we didn't want to lose the water softer, if he had proved to me that it was the cause of the issue, BEFORE we agreed to do all the additional work, i would have felt less bitter about it.

He quoted towards the end - "you've got all the answers, i'm just the muscle". Almost felt like i've had to tell him how to do his job in some ways. And he wasn't particularly cheap either.

Blimey, didn't anybody suggest changing the shower head?

Ha - I wish is was that simple. It's not just a simple hand held shower head. It's a large rainhead and waterfall outlet shower from porcelanosa which cost me just over a grand. I think I added some pic's in a previous post.

I've had a shower this evening and it's probably the best shower i've had yet - feels slightly better than what it was with the stuart turner monsoon pump (or maybe it's just in my head - but an amazing shower experience either way).

 

[kash]

Kingspan came out this morning to inspect the installation and they said the installation had been done to a good standard and there were no problems with the new set up. They would be happy to honour the warranty and commence the service plan.

Only question I have is.... the hot water thermostat was set at 65degrees before. The engineer said this was probably be a bit over kill the water would be quite hot to be able to touch and not so energy efficient. He set this to 55degrees. assume this is ok to do?

 

[SJB060685]

Kingspan came out this morning to inspect the installation and they said the installation had been done to a good standard and there were no problems with the new set up. They would be happy to honour the warranty and commence the service plan.

Only question I have is.. the hot water thermostat was set at 65degrees before. The engineer said this was probably be a bit over kill the water would be quite hot to be able to touch and not so energy efficient. He set this to 55degrees. assume this is ok to do?

Stored HW should be heated to 60°c to kill off any legionnella bacteria.

 

[ShaunCorbs]

As above needs to be coming out of the taps / stored at 60dc

 

[Chuck]

Only question I have is.. the hot water thermostat was set at 65degrees before. The engineer said this was probably be a bit over kill the water would be quite hot to be able to touch and not so energy efficient. He set this to 55degrees. assume this is ok to do?

Like every decision that trades off risks (salmonella vs scalding) there is no right answer. The consensus in the UK seems to be that 60°C is the sweet spot. The heat losses from a modern tank are so low anyway the savings are barely worth considering.

 

[kash]

Like every decision that trades off risks (salmonella vs scalding) there is no right answer. The consensus in the UK seems to be that 60°C is the sweet spot. The heat losses from a modern tank are so low anyway the savings are barely worth considering.

He did say this too. He said as the water is constanly flowing and in use the risk is super low. It would be more of an issue in static/stagnent water for long periods of time with no use.

 

[ShaunCorbs]

Happy with your shower experience now and that’s good of Kingspan

 

[kash]

Temp now adjusted to 60 degrees as per recommendations. Thanks all

@ShaunCorbs yes- shower is back to being amazing. Water has solid powerful output and plentiful. I’m back to taking longer showers 😀

Good of Kingspan yes- naturally there’s cost involved but it’s all within the service plan.

I’ll let them service it for the next two years at least as they cover all parts and labour within that time... then after that I’ll see how much a service is from an independent.

If it’s similar or not much more will just let Kingspan do the service as I get to spread the cost