New house hot water woes

[zooankski]

I will start with a bit of back ground info. We have just moved in to a really nice 5 bed/5 en-suite property which started life as a bungalow with 3 beds on the lower floor.
It is set back from the road by around 40 yards and has recently had the roof space converted in to 2 more bedrooms complete with en-suites so 5 beds and 5 on-suites!
Wet Uponor UFH downstairs and 2 rads in the upstairs rooms which all work great.
There are 2 adults and 2 children in the family.
The problem is the hot water or should i say lack of it and possibly a flow issue.
The house is fitted with a Santon 150 indirect tank and what i assume to be a secondary circuit with bronze pump that runs continuously back in to the cold feed. Could this be effectively radiating the heat away and is it worth removing it?
I had originally thought the water softener may be restricting flow to the showers as none of them are that great, but even selecting bypass does not really improve matters, also the hot water doesn't last long. I could live with the flow but not the quantity.
I have checked the water pressure at the outside tap this afternoon and had 2.4 bar and i just need to confirm the flow rate (which i will try and do today)
I suspect it will be fairly low due to the distance the house is set back from the road (built behind another property)
If this is the case then i cannot see any options available that would improve quantity and flow. We don't have a loft so that's out.
A different Indirect cylinder would be in effect useless regarding flow even if i increased it's volume and from my research a large combi would not cope with 2 showers at the same time which would realistically be the max as we don't do communal washing.
I have asked for a few companies to check out what the situation is and provide options and costs but does anyone have any suggestions?
Sorry it is a bit of a long winded explanation of our issue! I have included a few pics of what i believe is the secondary. Most of the plumbing is poly just out of shot.

 

[zooankski]

Picture of house so you can see the lack of loft area
I also found some pictures that the previous owners left me showing the supply install. The pipe looks a lot thinner at the house end although i could be wrong?
They also show the distance from the road.

 

[picasso]

Your 150 ltr cylinder is inadequate for your needs, 250ltrs should have been installed and depending on flow rate and pressure you may have to install a booster set, what was the pressure with a tap running ?

 

[Dan Robinson]

Or an accumulator ... Depending on space can help the flow. As said, 150 litres is too little.

The secondary return pipework (bronze pump) should be lagged and the pump on a timer and thermostat .

The pipe work looks a bit of a dog's dinner , but shouldn't affect flow too much . But until you give a figure it is all subjective .

 

[oilboffin]

With 5 bathrooms I'd say if all in use 250may be not enough.

 

[muggles]

As above, I'd be looking at at least 300 litres if you have space, and an accumulator (a second large tank which will store pressurised mains water to supply your home if the mains can't keep up). That bronze pump won't last long mounted like that - the head should be horizontal to prevent excessive wear on the bearings.

 

[dilalio]

Agree with all the above.
What size is that blue poly?
Lag as much of the recirc as you can and increase cylinder size or add another cylinder if room.
Accumulator to boost flow and pressure if your readings are low, you want at least 16lpm.

 

[Doggit]

I can't see properly from the camera angles, but in pictures 2 and 3, it almost looks as though the 22mm pipe goes down to 15mm, and there's then an isolating valve on it, and all that would reduce the flow. And there seems to be quite a few of them as well.

 

[dilalio]

I can't see properly from the camera angles, but in pictures 2 and 3, it almost looks as though the 22mm pipe goes down to 15mm, and there's then an isolating valve on it, and all that would reduce the flow. And there seems to be quite a few of them as well.

Yes! And are they full bore ballofixes?

 

[Steelmasons]

Yes! And are they full bore ballofixes?

They don't look like full bore..

 

[dilalio]

They don't look like full bore..

Exactly!

 

[picasso]

Looks like we have two methods of sizing cylinders, count the number of people living at the property or count the number of bathrooms all running at the same time, I wonder if there is another way using loading units and stuff.

 

[Doggit]

Forgot to mention that with a recirculating system, you need to make sure that the pipes are well lagged, otherwise it's just acting as an underfloor radiator. The system means that you always have instant hot water whenever you open the taps, but I'm not convinced on them. I think the overhead heat required to maintain the constant flow, doesn't add up.

 

[Echo the husky]

I love 'em! I don't want to wait for hot water!

 

[zooankski]

Got some initial feedback on pressure etc. 2.4 bar static, 2 dynamic and 14-16 litres/min.
I did think the recirc would act like a rad so have disconnected the pump to test. Other than the fact that it takes about 4 minutes minimum for water to get hot at the furthest bathroom, I actually managed to have a very nice hot shower for a change!
Got another plumber coming to check it out tomorrow. Plumber today said he could possibly add a second 150 tank and accumulator.