Slow Running Hot Tap.

nottslass_2

Hi, I was wondering if there are any super duper plumbers who can shed any light on my problem ?

Had a new bath with shower mixer taps fitted last week. Anyway the Hot water tap is now really slow - Takes about 10/15 mins to run a bath !!

The plumber has basically blamed the taps I purchased ( without looking for any other explanation,such as air lock etc) saying that they are not compatible with my Condensing boiler & I'll need new taps (which of course he'll supply & FIT FOR A COST)

Is this correct or should I be asking for a second opinion ?

Many thanks for any help.

Nottslass

andrew-b

Are we right to assume by condensing boiler you mean a non-combi boiler with a hot water cylinder in a cupboard and cold water tank in the loft? (Bit picky but combi boilers are also a type of condensing boiler!).

If so then you need taps designed to work at a low pressure of around 0.1 bar to 0.2bar water pressure. I'm guessing you've supplied taps suitable for higher pressures only.

What make and model of taps did you purchase?


To be fair though if you've supplied him the wrong taps it's not really the plumber's fault..however I would have hoped a plumber would have told you the taps you supplied him were unsuitable before he fitted them - assuming he actually realised.

nottslass_2

Thanks for taking the time to answer andrew - Yes,I've got a hot water cylinder in the airing cupboard & tank in the loft.

The taps I've purchased are Diva Elan taps ( model 106) - does this mean I doomed & need to buy a more suitable tap or are they salvageable ?

Thanks again

fox12

The only reference on the internet I could find to these types of taps where 'Deva Elan Mixer taps

Unfortunally it does state for these taps:
high pressure - works on a minimum pressure of 0.5 bar or above

If your hot water tank is on the same floor as your bathroom then your water pressure will only be about 0.1 - 0.2 bar.

Unfortunally we live in a world now were most installers are just fitters and dont really check into what they are installing. It would be very hard though i would guess to get the fitter to change these free off charge

If you would like to increase the flow rate of your bath mixer tap I would suggest changing it for a low pressure mixer tap which is generally a tap with a seperate hot and cold control.

A smile and hot cuppa and he might change them for a reduced rate though

andrew-b

Spec here: http://www.deva.org.uk/products/detail1/bathroomtaps1.php?imageField4.x=33&imageField4.y=52&category1=bt&range1=elan ...0.5bar minimum which = high pressure (106/DM model is the same 0.5bar according to elsewhere).

Your options are either to replace...or to have a suitable pump fitted to boost the pressure up beyond 0.5bar to make the supply high pressure (assuming big enough tank & cylinder). But none of the taps in the same range requiring 2 holes in the bath seem suitable).

Check you basin taps too..models 113 and 313 in that range are 0.3bar..others basin taps in the range are all 0.1bar upwards from what i can tell. Probably not as noticeable if you've got the wrong one's there though so if it's not a problem i'd leave be! Though if you've now got to get new bath taps they probably aren't going to match anymore!

Whatever you have to replace i'd put on ebay if i were you to cut your losses...so long as they are removed carefully should have some resale value in them hopefully.

If your looking for alternatives have a look at Crosswater Komo (we've got some crosswater komo basin taps from https://www.homesupply.co.uk )..similar styling but 0.2 bar upwards though slightly more expensive. I think Bristan do a similar style of tap too.

andrew-b

fox12 wrote: »

If your hot water tank is on the same floor as your bathroom then your water pressure will only be about 0.1 - 0.2 bar.

The rule of thumb is 0.1 bar for every metre head of water ...i.e. distance from outlet to base of cold water tank above. A standard room height is around 2.5m.. so if the tank is on top of the ceiling joists and accounting for height of the bath your just about at 0.2bar.

nottslass_2

Thank you - you certainly "know your taps"

andrew-b

I spent an age searching for my own low pressure one's..bit of a minefield to be honest if you don't understand what your looking for! Much easier finding taps if you have a combi or unvented system as then any tap will do (if your considering either systems in the near future i'd make do as is).

oh and a few other makes we considered ourselves ..Grohe do some low-pressure ranges (eurodisc range i think - similar styling), Ideal Standard do a couple of ranges of low pressure one's (Alto and Cone i think i was considering), also Mayfair was a cheaper brand i considered (dont remember model), plus Bristan and Crosswater.

keystone

nottslass wrote: »

Hi, I was wondering if there are any super duper plumbers who can shed any light on my problem ?

Had a new bath with shower mixer taps fitted last week. Anyway the Hot water tap is now really slow - Takes about 10/15 mins to run a bath !!

The plumber has basically blamed the taps I purchased ( without looking for any other explanation,such as air lock etc) saying that they are not compatible with my Condensing boiler & I'll need new taps (which of course he'll supply & FIT FOR A COST)

Is this correct or should I be asking for a second opinion ?

Many thanks for any help.

Nottslass

The "plumber" is correct but he shouldn't have fitted them in the first place f he knew this problem was going to exist which he should have done.

Some posters have correctly commented on the "works down to "n" bar" specification for these taps and thats the root of the problem because in most cases the manufactures are actually spinning their marketing. Another has correctly mentioned about the static head from a gravity system.

However, the problem is nothing to do with pressure but everything to do with flow rate. In general:

1/4 turn ceramic disc taps are very restrictive.
Isolating valves (water regs) are required if not full bore again restrictive
If flexis tap connectors used again very restrictive (22mm flexi don't give more than about 13mm bore)

IMHO he should have warned you about this BEFORE starting to fit and given you the opportunity to change the taps.

Now 15 mins to fill the bath aint that bad actually that bad. I've been to places where its been nearly 45!

You actually have 4 choices:

Live with it.
Replace the taps with conventional ones - there are plenty of modern style taps which still have conventional head gear
Remove some of the restrictions to flow in the plumbing
Pump it.

Cheers