Replacing Central Heating Pump, replace isolation valves?

Discussion in 'Plumbers' Talk' started by Bill The Bolt, Oct 9, 2018.

  1. Bill The Bolt

    Bill The Bolt New Member

    This weekend I'm planning on replacing my central heating circulation pump as it's starting to get a little noisy and I'd rather replace it now before it gives up the ghost altogether. It's a straightforward job, my only question is, would it be a good idea to replace the existing isolating gate valves with full flow ball valves?

    The reason I ask is that I recently changed the float valve feeding my cold water tank in the loft and when I attempted to shut off the supply with the original gate valve, it would not shut off completely, meaning I had to isolate the whole house at the stop cock. Can anyone suggest a decent full flow ball valve for this job?
     
  2. Pollowick

    Pollowick Well-Known Member

    Changing the valves will require draining down at least partially. Most of the time they will be fine, but change them if you need and just go for pump isolation valves - I doubt if you can get full bore valves with the right thread size at a sensible price.

    Which pump are you going to install?
     
  3. Bill The Bolt

    Bill The Bolt New Member

  4. Bill The Bolt

    Bill The Bolt New Member

  5. The Teach

    The Teach Well-Known Member

    The above linked valves are not the best,have a look at the sf reviews (low to high) for their 22mm pump valve (same valve different size) :(

    Pegler do decent pump valves ;)
     
    Heat, KIAB and retiredsparks like this.
  6. Dave does Gas

    Dave does Gas Well-Known Member

    In my experience when it comes to pump valves the gate stlye valve always wins hands down. It is frustrating regularity that the ball valve style leak from the gland, where as its rarely a gate valve fails and if it does the system can always be bunged to replace the pump and valve. But its a brave DIY'er who would attempt that.
     
    KIAB likes this.
  7. Heat

    Heat Well-Known Member

    The full flow Peglers pump valves are the same inside as full flow lever valves and are therefore top quality.
    They use special seals made of a hard type of ptfe.
    I highly recommend them and have a pair of 22mm on my pump (and I am a heating guy).
    One thing to note is the large nuts on Peglers valves cannot be replaced, whereas the gate valve type pump valves have removable nuts, which can be purchased. Handy for seized or damaged nuts.
    The cheap pump valves with a ball in them are useless as they have rubber seals and leak and seize. Never use them!!!
    Not sure if you can buy 28mm Peglers pump valves as I have only seen them in 22mm and perhaps best to buy standard gate type pump valves which generally work ok.

    A gate valve on your mains supply to heating tank is the wrong valve. Gatevalves are not really a watertight seal for such a job.
     
  8. KIAB

    KIAB Well-Known Member

  9. Heat

    Heat Well-Known Member

    KIAB likes this.
  10. Bill The Bolt

    Bill The Bolt New Member

    Thanks everyone for the great advice, will go with Pegler pump valves. With regard to the cold water tank feed, this was replaced with a Pegler lever arm ball valve when I replaced the float valve.
     
  11. The Teach

    The Teach Well-Known Member

    dont throw away your vibrating pump it will have some use :) think about the coldest winters day and your new pump fails.
     
    KIAB, Heat and Pollowick like this.
  12. Pollowick

    Pollowick Well-Known Member

    If you do not already have it, have a look at the Grunfos Alpha 2L, you can get them at teh same sort of price and they are an even better pump.

    Having had a pump fail, I know the benefits of that! I took the pump from my underfloor heating and installed on the main CH as a temporary measure.
     
  13. Heat

    Heat Well-Known Member

    I used to scrap most still functioning circulating pumps if they were fairly old.
    But now I look at them as better than the new types
     
  14. Bill The Bolt

    Bill The Bolt New Member

    Thanks again everyone, some really good advice. Will certainly consider the Grundfos Alpha 2L before making a final decision.
     

Share This Page