Extra feed from Cold Water tank required

[Derek]

Hi all

I am installing a pump for a shower which requires a separate feed from the cold water tank. I have a plastic (50 gallon) tank in the loft and intend using brass tank connector with compression fitting into 22mm copper pipe (just like the existing feed to the hot water tank). Q1. What tool should I use to cut the hole in the tank (holesaw in a drill or hole cutter)? Q2. The hole need to be as low as possible. I obviously need to avoid internal structures (strengthening webs, etc.) but are there any other guidelines for positioning the hole? Q3. What do I use to seal the tank connector / tank joint? The tank connector comes with no washers - can it bolt straight on to the tank? Should I use a washer / silcone sealant?

Thanks in advance.

Derek

[Andy Hall]

A proper hole cutter (i.e. individual cutter that screws onto an arbor) is highly recommended compared with one of the sets of saws with concentric thin blades. It will cut a cleaner hole at much lower risk of cocking up your tank.

Below the outlet to the hot cylinder. If you can't sensibly achieve that, then make a hole at a level above and move said feed to a fitting in the new hole. Use the existing one for the cold.

Yes. Generally there should be a soft plastic washer for the inside and outside (or possibly fibre). I smear faces with silicone (not acrylic) sealant.

[Dave Fawthrop]

| Hi all | | I am installing a pump for a shower which requires a separate feed from the | cold water tank. I have a plastic (50 gallon) tank in the loft and intend | using brass tank connector with compression fitting into 22mm copper pipe | (just like the existing feed to the hot water tank). | Q1. What tool should I use to cut the hole in the tank (holesaw in a drill | or hole cutter)?

Just make sure it is *round*, the right size and deburred.

| Q2. The hole need to be as low as possible. I obviously need to avoid | internal structures (strengthening webs, etc.) but are there any other | guidelines for positioning the hole?

Make sure the water is drawn off *slightly* above the bottom. You get grot in the bottom of tanks which you do not want in your shower.

| Q3. What do I use to seal the tank connector / tank joint? The tank | connector comes with no washers - can it bolt straight on to the tank? | Should I use a washer / silcone sealant?

Plastic washers sealed fine in mine,

[Dave Plowman (News)]

Since accessibility is good, I'd use a Q-Max punch. This will give a perfect hole - and will cost about the same as a complete hole saw. Any decent tool or engineering supplier will stock them.

[mcbrien410]

Take this opportunity to clean out the tank after you've drilled the hole. I've used polythene tube (Wine making) to syphon out the last drop.

Chris.

[Dave Fawthrop]

| Take this opportunity to clean out the tank after you've drilled the | hole. I've used polythene tube (Wine making) to syphon out the last | drop.

You forgot to mention a cloth to remove the semi solid grunge. :-(

[jjj]

I'm in the same position - installing a Salamander RHP75 whole house pump.

The installation manual states that you need 50 gallons minimum per bathroom - or 80 gallons min. for a bathroom + ensuite shower room.

I too have a 50 gallon tank - however I had a peek in, and it was only about

2 thirds full (is this usual?). I measured the water height, width depth, did the calcs in the salamander inst. manual, and it came out at 40 gallons in the tank. - eg. about half of what I need (80 gallons).

I'm thinking about putting another tank alongside the existing one and hooking them together with 28mm pipe to get the required capacity.

Questions are - would I need 2 ball valves? would I need 2 overflows? or can I just treat the whole as one big virtual tank??

[Andy Hall]

I've done this in the past in a house where I needed more tank capacity and the place to fit tanks was an awkward shape.

There are several things to consider:

- Loading. Do make sure that the support is adequate - e.g. over a structural wall or equivalent.

- Water inlet should go to one tank. You may find it beneficial to fit two float valves to the same tank, since most do restrict the flow available from the mains somewhat.

- Connect the tanks together as you have described with a piece of

28mm pipe near the bottom of the tanks.

- Take all outlets from the second tank to avoid stagnation of water in either tank.

- Fit an overflow to both tanks. It's unlikely that the connecting pipe would block or any other reason why one tank could overflow, but there is no need to tempt fate.

[Derek]

[Andy Hall]

You're welcome.

It's worth checking the tank connectors in a few days to make sure that there is no seepage. There shouldn't be, but it doesn't hurt to be sure.