Low level cold water tanks

Discussion in 'Plumbers' Talk' started by fostyrob, Oct 16, 2018.

  1. fostyrob

    fostyrob Screwfix Select

    Hi all,

    Was looking for a bit of reassurance as to what I propose to do is the correct course of action.

    Essentially we have just started to use the heating and noticed that one of the kids radiators no longer works. The trv pin was stuck but despite freeing it no success. The valves are very old and I suspect has seized shut.

    Our tanks in the loft (both f&e and cold water) are again very old and totally uncovered so as expected full of years of crud and as we have an old horsehair slate roof bits of horse hair. My intention was to wait until warmer weather and replace the lot with new covered and insulated tanks but my hand really has been forced by this radiator.

    I don't want to drain down and distribute all this gunk through the system for the sake of the radiator so am going to bit the bullet and just do it all just now.

    Here is the problem.

    As the boiler (for upstairs- yes for some reason we have two small ones) is in the attic the f&e and cold tanks are crammed into the apex of the roof on a timber frame. A room (of sorts) was built underneath this area and used as a sort of office by the old occupants so there is not really much scope to change the position of where the tanks are situated.

    The f&e is not a problem but getting a suitably sized cold tank into this area is proving problematic. The one currently there is 540mm (h) x 580mm (w) and ~1000mm (l). As not full I'm guessing it is probably somewhere between the current 50 and 70gallon tanks. Preferably I was wanting a similar sized tank and with a growing family and likely increasing demands would like a 70gallon.

    Length is not an issue but wherever I have looked they all seem to be fairly standard sizes. The 70 gallons all seem to be about 610 wide and although they are slightly less tall (500mm) because of the position in the roof apex will likely not fit without trimming the lid round joists which is not really a feasible option.

    What I propose is to fit two smaller tanks in parallel with dual cold feeds, wastes etc. I assume this is the best way to approach the situation rather than trying to bodge two tanks together in series with connecting low level pipes (sure it is possible but seems like it could be a recipe for disaster). Would welcome any thoughts or if anyone knows of a source of really long, low and narrow coffin type tanks which would be the best solution.

    Apologies for the long post and thanks in advance.
     
  2. KIAB

    KIAB Super Member

  3. fostyrob

    fostyrob Screwfix Select

    Thanks KIAB. Checked out this website already. If I was going to go with a single tank (70gallon) these tanks will not fit. They are only marginally wider than what is already in place (610mm cf. 580mm) but this means they will not fit because of the slope of the roof. The current tank is 540mm tall which is smaller than current tanks but this is also without a lid.

    Believe me I have measured and re-measured but these tanks just will not go in. If they just made a narrower and shallower coffin that was for instance 2m long that would be perfect but alas I cannot find one.

    It is this that has led me to the conclusion that I am going to have to use a combination of smaller tanks.
     
  4. Pollowick

    Pollowick Screwfix Select

    Have a chat with Polytank http://polytank.co.uk/polytank.html They have an extensive range and also good tech support who can advise on the best use of two tanks - whether you have series, flow into one, 28mm connecting pipe and take off from the other or both, OR two parallel tanks.

    They do a 190 L (42 gal) tank in their rectangular range, 510 wide 490 high 1185 long - so two of those with a 28mm joining pipe.
     
    fostyrob likes this.
  5. fostyrob

    fostyrob Screwfix Select

    Cheers will give them a call. From a brief look they do seem to have slightly more choice but measurements seem similar- no elusive superlong tank (bit of a niche market I'm guessing).

    Many thanks
     
  6. Pollowick

    Pollowick Screwfix Select

    Problem with a super long would be transporting and moving into place and maybe overall rigidity. Two of the 190 litre connected together would work - narrower and shorter than existing so you would be able to get them in easily enough.
     
  7. fostyrob

    fostyrob Screwfix Select

    polytank advise creating the "frankentank" and connect two together rather than going down the tanks in series approach. Connecting pipe to be equal or greater than draw-off pipe.

    Right now have to come up with permutations of smaller tanks that will fit. Access is a nightmare and have a feeling this is going to turn into a pig of a job!
     
  8. Isitreally

    Isitreally Super Member

    If you're happy the tvr pin is free the rad probably has sludge in it, with the heating on and all rads bar this one closed off, bang the bottom half of the rad with your fist to try and free up the sludge once it start to move the heating pump should push it around the system as it breaks up, this method work great for me a couple of weeks back
     
    fostyrob likes this.
  9. fostyrob

    fostyrob Screwfix Select

    Oddly enough access is pretty good as the attic has half been made into a room with the tanks accessible from a removable panel. All connections currently are at the accessible end so intallation of the superlong would not be a problem. With the two tanks the mid connection is going to be tricky but will have to find a way!
     
  10. fostyrob

    fostyrob Screwfix Select

    I think it is the valve to be honest. The pin can be pulled back but it is not free moving. Push it back and it will stick.

    As you say it could be sludge as the tanks are mucky and this radiator is on 8mm microbore. Ordinarily I would flush some sentinel x800 but don't want to flush through the other nasties within the f&e and end up with more blockages.
     
  11. Pollowick

    Pollowick Screwfix Select

    So, connect two together, feed into one and take from the other - surely that would make it series! I understand that you should not feed and take from just one as that could cause stagnation in the second tank. By feeding one and taking from the other, you then get a good water flow/circulation

    As for connecting together. As you say, it needs to be equal to or greater than take off, which is why I suggest 28mm. Dry fit at ground level with 28mm outlets and short lengths of pipe (copper or PEX). Then, use a push fit (Hep2O) connector to join the lengths when installed in their final positions.
     
  12. Pollowick

    Pollowick Screwfix Select

    A quick squirt of WD40.

    Have you got a Mag Filter fitted? If so, you can with some (ADEY for example) use that to dose the system. Or there are fillers to allow you to add through a radiator.
     
    fostyrob likes this.
  13. fostyrob

    fostyrob Screwfix Select

    Apologies- I meant polytank advised against a parallel setup (but I typed series). Series setup is the way to go.

    No filter on the upstairs setup- that is another task. The downstairs has a fernox tf1 omega that seems to be doing a good job.

    To be honest rather than much around with trying to break up the crud I just have to get on with new tanks, whole system drain down, flush and re-dosing. The systems needs some tlc! Interestingly I have found that the drain off comes directly out of the external wall above one of the windows - probably change that too!

    Don't have any 28mm to hand but loads of 22mm CU but I guess the larger diameter will allow better tank circulation.
     
    Bargain Bucket likes this.

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