# Help - what connections do I need ?



## tubamanandy (24 Feb 2014)

Just having a new kitchen and thought I'd take the opportunity of asking the fitters in the UK to plumb my standard 3-pod 10" HMA (1 x pre-filter & 2 X carbon filters) filter into the hot and cold water system as I'm currently piping it from the shower through the HMA and then to the tank.

Any idea what would be the best setup ? Unit is going under the sink and there is a hot & cold feed. I need some form of mixer so I can adjust the temperature of the water.


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## Edvet (25 Feb 2014)

What's a HMA filter? Resin?


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## tubamanandy (25 Feb 2014)

No, simple standard 3-pod system, pre-filter & 2 x carbon blocks - similar to what you see under RO units. I thought they were known at HMA filter (I maybe wrong)


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## Paul Butler (25 Feb 2014)

HMA filters were "invented" or brought to the market by a chap called Mark Evenden who is a discus retailer. Typically they consist of a pre-filter, a carbon block or some sort and a carbon resin type filter which removes heavy metals. The last cartridge used to be a Pentek CBR2-10 which is the heavy metal doobrie. HMA stands for Heavy Metal Axe fwiw. No need to use dechlor agents with these, and no waste water either as per an RO. 

People I know who mix hot and cold use a shower mixer unit to do this. Use John Guest fittings to connect the piping to washing machine outlets, these are 3/4" BSP so you need the 3/4" FT to 1/4" PF fitting. If you use the shower mixer you will need the same again plus 1 for the outlet to the HMA I think.


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## ian_m (25 Feb 2014)

Pegler Prestex TMV2 Thermostatic Mixing Valve 15mm | T&#39;static Mixing Valves | Screwfix.com
You put one of these before your HMA to mix the hot and cold. You can get much cheaper equivalents from Ebay. Remember check valve on both hot and cold to prevent back flow, though might be present in Pegler one.

If your cold is quite high pressure (ie greater than 5bar) and hot is gravity fed you will need a pressure reducer on cold supply. Honeywell Pressure Reducing Valve with Gauge 15mm | Pressure Reducing Valves | Screwfix.com. Again cheaper equivalents on Ebay.


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## tubamanandy (25 Feb 2014)

Thanks for the info Ian M, just what I was looking for. I also want to control the flow rate so I guess I will need some form of tap as well.


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## ian_m (26 Feb 2014)

You will also need these on the hot supply to stop higher pressure cold going back up the hot
15mm Single Check Valve | Check Valves | Screwfix.com

And one of these on the cold supply, to comply with water regulations. This is to stop your water going back up the supply if the supply fails.
15mm Double Check Valve | Check Valves | Screwfix.com

Use one of these to control your flow.
Pegler Ball Valve Blue 15mm | Ball Valves | Screwfix.com

If I was doing it I would fit one of these with the rest of the above kit just before your plumbing goes to hose pipe.
 Water Valve Solenoid G1/2 1/2&quot; BSP 220V 230V 240V Coil Irrigation Hydroponics | eBay 

Connect to a long lead & switch & power at other end of hose pipe near your tank. Thus when your tanks is full, flick the switch to turn off the water. Easy to empty water in hose as not pressurised.


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## Edvet (26 Feb 2014)

Oh man, so happy to live in a place with excellent drinking water, cheap, clean and reasonably soft.


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## tubamanandy (26 Feb 2014)

Ian, one very last question:-

What is the fitting I need from the 10" pod (pre-filter) to the flow controller ? I've ordered all the rest of the parts (except the water solenoid,,,for now). The plumbers will be using the 15mm plastic pipe everyone seems to use these days. I just dont know what connection to buy thast will connect the plastic pipe to my 10" pod.


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## ian_m (26 Feb 2014)

tubamanandy said:


> Ian, one very last question:-
> 
> What is the fitting I need from the 10" pod (pre-filter) to the flow controller ? I've ordered all the rest of the parts (except the water solenoid,,,for now). The plumbers will be using the 15mm plastic pipe everyone seems to use these days. I just dont know what connection to buy thast will connect the plastic pipe to my 10" pod.


I would take it to a plumbers merchant and say I want to connect this (your filter) to this (15mm plastic pipe).

Quick look on Ebay reveals 10" filter pod as 3/4" female fitting.

Thus 3/4" male to 15mm will do.
Male Coupler 15mm x ¾&quot; | Compression Coupling | Screwfix.com

Just make sure it is a straight thread (as opposed to tapered). Again a proper plumbers merchant, will be able to help you.


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## tubamanandy (26 Feb 2014)

Ian, I've now got all the parts on order & really happy.

Only thing I could really do with knowing now is what order the parts should technically go eg. cold feed to double check valve, hot feed to single check valve, both check valves to mixer then mixer to thermostatic valve then thermostatic valve to filter. Some form of schematic would be great so I can be sure plumber does it correctly


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## ian_m (26 Feb 2014)

Hmm. ImageShack is no longer free, so can't load my picture.

- Hot supply is single check valve then to thermostatic mixer.
- Cold supply is double check valve then to thermostatic mixer.
- Output of mixer to isolating valve then to filter. You need this valve so you can isolate the filter to change the filter cartridge.
- Output of filter to another valve then to hose connector. This valve controls your water flow.

You need the two valves, especially the one before the hose as if you went with just one valve before the filter, you will find water will drip/escape from the filter output as it is now just open to the world.


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## tubamanandy (26 Feb 2014)

Excellent help again Ian, I've now drawn the schematics for the plumber so hopefully he cant get it wrong


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## ian_m (26 Feb 2014)

You can of course use flexible 15mm hose (Flexible Hose 15mmx15mmx10mm bore 300mm | Compression Hoses | Screwfix.com) to get your valves, filters and hose connectors in easy to access places rather than rely on masses of copper/compression/push fit fittings connecting the lot together.

Other point, as seen on water board site, virtually no UK water supplier has any "heavy metals" in their water that the HMA could remove. However they will remove any lead in the water from consumers house (a moot point again as generally lead is not present despite lead piping as it is generally coated with limescale, in soft water areas with lead piping the supplied water is artificially hardened so as to coat lead pipes) and will of course also remove chlorine and chloramine.

http://dwi.defra.gov.*uk*/consumers/advice-leaflets/*lead*.pdf


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## ian_m (27 Feb 2014)

Whoops we forgot the pressure reducer on cold supply, after double check valve. You will need pressure reducer if you are trying to mix mains water pressure with gravity fed hot water. If you are mixing tank fed cold and hot no reducer is needed.

I have a thermostatic mixer and mains water pressure reducer in our bathroom for the sink so that when the kids were younger they wouldn't scold themselves on hot water. Fitted in 2004 odd and still working.


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## tubamanandy (27 Feb 2014)

We have a combi system so do we definitely need the pressure reducer on the cold supply ?


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## ian_m (27 Feb 2014)

tubamanandy said:


> We have a combi system so do we definitely need the pressure reducer on the cold supply ?


Probably not in that case as the hot water via combi will hopefully be at mains pressure or at least greater than tank gravity fed pressure. Talk to you plumber and/or read boiler instruction manual, as some combi do have pressure reducers built in.


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## tubamanandy (27 Feb 2014)

Cheers again Ian - when the system is up and running well I will probably add the solenoid for a bit of sophistication


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## ian_m (28 Feb 2014)

tubamanandy said:


> Cheers again Ian - when the system is up and running well I will probably add the solenoid for a bit of sophistication


Reason I would add the solenoid for control of water flow from tank end, is I ran for ages with 40l buckets of mixed water in kitchen and a JBL u750 pump on a remote control main socket. Brilliant, when tank is at required level, turn of pump remotely, no rushing back and forward to turn water off.

I was thinking of putting one of these Buy Level Sensors &amp; Switches Miniature 140 VAC vertical float switch RS PLS-031A-3 online from RS for next day delivery. only £5 odd, hang over edge of tank and turns water off (remotely) when tank is at required level.


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## tubamanandy (11 Mar 2014)

Ian, plumber fitted above system yesterday and it works perfectly !!

Water comes out at 30C (which is the lowest setting of the thermostatic valve I ordered from EBAY).

Thanks very much again for your help


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