What type of pump for tank fed system?

goz83

I am having the bathroom revamped after having some internal insulation done in the hall and bathroom. The taps are the RT Large ones, so they're 0.2 bar pressure. I am waiting for the mono basin mixer and currently have the bidet mixer on the basin, but the pressure is poor. The set up is like so:

Bathroom on first floor with the immersion boiler on same floor. Cold water is fed by gravity flow tank in the attic. Attic is converted, so tank is lower than standard height and reduces water pressure. I would leave it as is, but the bidet tap will be useless with the current pressure and I would also like the bath shower mixer to have some decent pressure for cleaning. We have a Triton T90 Z replacing the old Triton T90 SI. I am thinking a 1.5 bar pump will be sufficient, but what type of pump should I use? I can't for the life of me think of the type needed. One with one of those bell type things on top I think? I don't know whether it should be installed in the attic, or where the boiler is. Your advice will be kindly received....and even better if you know where is the best place to buy. I'm in Dublin 13 and think either Heat Merchants, or buying online.

goz83

Ok, so i've been doing my research. A well known plumbing supplies outlet said I needed a brass bodied pump if I was using it to supply a sink and bidet. The price for a 1.5 positive head was €488. That's a bit much I think. I ordered a techflow neg head pump from ebay last year for my dads apartment. It's not a brass body. its a QT ***** 3.3 bar double ended unit and it supplies the sinks and toilets in the main bathroom an ensuite. It supplies the bath and it supplies the mixer shower in the ensuite. So why would I need a brass bodied pump to supply a sink, bidet and bath?

According to the technical guy at techflow, I don't need a brass unit if I am supplying the above and as long as the pump (a 2.3 bar unit http://www.ebay.co.uk/itm/Techflow-Quiet-2-3-Bar-Shower-Pump-Booster-Power-QT80T-/130508186368?pt=UK_Home_Garden_Bathroom_Shower_Units_PP&hash=item1e62e4e300#ht_3881wt_1393 ) is put in beside the cylinder, below the cold water water storage, the pump I have linked is fine. It's also more powerful and half the price and quieter if my dads one is anything to go by.

I just don't want to make a mistake, because we had to exchange a positive head for negative head pump at my dads apartment from techflow. The error was mine and I don't want to make that mistake again.

JohnnieK

Techflow negative head pumps are always breaking down in appartments. Builders got them by the truck load in the day for cheap. The one in the picture looks cheap too.

I've always gone with Grundfoss as I've never had issues with them and there is good back up in this country.

Joey the lips

If your continously using the pump for taps as you will be you will need a brass bodied continous rated pump. Your plumbers providers is right. The cheaper non continous rated pumps come in about 200 euro.

Also bidet mixers are high pressure so its hard to see the pressure problem.

I would also have a review of your plans to put a T90 over the bath if you have a bath shower mixer it can look very very untidy.

In your situation if you buy a pump greater than 1.5 bar then your cylinder in the hot press will run cold very very quickly so you will be introducing more problems into your life.

I would caution you and say there is very rearly a cheap plumbing fix to your situation but if your going to buy a that is cheap make sure you buy good low pressure taps or likewise if you buy a pump that is expensive then you can buy cheap high pressure taps(once they are not higher rated than the pump)

lastly. a pump retrofitted to a system will require fitting in such a way it does not drag air into the lines the low cost plastic pumps fail a lot quicker than continous rated pumps here..

mattluketudge

A great place to buy a set of bidet mixer taps is - <snip>

please read the forum charter before doing that again.

goz83

Joey the lips wrote: »

If your continously using the pump for taps as you will be you will need a brass bodied continous rated pump. Your plumbers providers is right. The cheaper non continous rated pumps come in about 200 euro.

I have been getting mixed information on this. I understand the brass body ones are more robust, but the techflow qt 3.3 bar pump my dad has served him well with no problems and gets a decent amount of use. I have ordered one from the UK, the new QT120T twin head I posed above. I got it cheaper, from Plumb Warehouse at £260, which is £60 cheaper than the other place selling on Ebay. I had to arrange a courier myself, but it was Plumb Warehouse who suggested I use parcel2go.com, which was easy to use and saves me a fortune. Fingers crossed it all works out.

Joey the lips wrote: »

Also bidet mixers are high pressure so its hard to see the pressure problem.

I didn't know this at the time of ordering. I thought all the taps were low pressure, but the bidet mixer is not. This is the only reason I need a pump! but it is more hassle plumbing it up separately, so I decided to pressurise the lot.

Joey the lips wrote: »

I would also have a review of your plans to put a T90 over the bath if you have a bath shower mixer it can look very very untidy.

I used to design bathrooms, so I am aware of this. The bath looks like a double ended bath, but has a recessed end for showering, which is where the waste is located. The BSM is set up in the middle of the bath, against the wall, putting it out of the way and making for easy cleaning. The T90 will be on the same wall (original placement) at the showering end of the bath. I am thinking about putting it on the connecting wall, but this will mean extending pipes and making fitting a bit trickier.

Joey the lips wrote: »

In your situation if you buy a pump greater than 1.5 bar then your cylinder in the hot press will run cold very very quickly so you will be introducing more problems into your life.

The cylinder has had to be replaced, as the old one was damaged. I opted to get a larger one. That should solve the problem. Hot water will really only be used when running a bath for the kids, so I predict one fill per day. Prior to this, we had no heating element in the old cylinder and only had hot water for a few months when the boiler was turned on.

Joey the lips wrote: »

I would caution you and say there is very rearly a cheap plumbing fix to your situation but if your going to buy a that is cheap make sure you buy good low pressure taps or likewise if you buy a pump that is expensive then you can buy cheap high pressure taps(once they are not higher rated than the pump)

True. Budgets are normally broken and have already been broken for this unplanned project.

Joey the lips wrote: »

lastly. a pump retrofitted to a system will require fitting in such a way it does not drag air into the lines the low cost plastic pumps fail a lot quicker than continous rated pumps here..

If the QT120T fails in time, I will be reporting it back here. I'll do the same if my dads neg head one fails. That's been in place about a year.

mattluketudge wrote: »

A great place to buy a set of bidet mixer taps is - ]

Thanks, but I already have the taps.

Joey the lips

Oh i did not realised you designed bathrooms. You seem to have it all sorted so. All the best. Happy showering.

goz83

Yes. The aesthetic and fitting side of things. It's the plumbing end that I can get confused about when it comes to pumps and that. Just rarely ever came up and there was always someone else who sorted out that part of the plan.

goz83

UPDATE:

So the pump has been installed several months now and it's been working great. I also had to order a diverter valve (not sure if that's the right name) so the pump wouldn't be under too much pressure. Techflow recommend this part if the pump is being hooked up to several things. Everyone is impressed with the bathroom. It's not tiled in Gold, but it looks well and is more than functional. The BSM makes cleaning the bath a doddle with the reach and power. I put in a new T90 and relocated it a few inches to the connecting wall, to minimise the potential for splashing water onto the floor. The bidet is great. Hot curries are no longer a concern.