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Which replacement central heating pump

Discussion in 'Plumbing and Central Heating' started by cooa99, 24 Apr 2021.

  1. cooa99

    cooa99

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    I have a feeling my existing pump is a potterton .... considering that the prima 40F boiler, (original) programmers and 9 radiators are.

    Looking for a drop in replacement is showing a few different units with a very wide price range. Please which would be ideal one to go for ?. A pic below if it helps.

    Also while I am at it, Can I fit a Magnaclean filter on a section of visible pipework from the Motorised valve ?. I think space under pump might be good enough.

     
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  3. Mottie

    Mottie

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    I think I read that a mag filter should be fitted as near to the boiler as possible on the return side. That’s where I have mine. Grundfos is a good make of pump as far as I know. I’m sure some heating engineers will be along to correct me though!
     
  4. Gasguru

    Gasguru

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    That's a pump made by a UK company called Circulating Pumps...and at one time they were owned by the Myson/Potterton brand.
    They now make the Wilo pump below under licence branded as a CP or Flomasta pump.

    A Wilo Yonos Pico 25/1-5-130 or Grundfos UPS3 15-50/65 would be the sensible choices.

    In the history of pumps both makes have screwed up big time but they are stable designs now.

    Don't waste your time with smart pump settings or features...there's nothing smart when the rest of the system doesn't know about them.

    Ideally filter on the return but it's not as though they pick up all the muck in one go..
     
  5. cooa99

    cooa99

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    Thanks both. I'll go with 1 of the pumps. Good they are available at screwfix.

    Regarding the Filter. I checked Adey website and the best location is return to the boiler. The next possible location is between the pump and the 1st radiator hence the location immediately after the pump in my 1st picture which 'may' appear to be an easier job for my DIY skills.

    However ...

    The return to my boiler (in the kitchen) is in the picture below. I only have a clearance of about 240mm between the ceiling and top of the boiler. What I don't know is if cutting the pipework to fit the filter as shown is allowed, I am worried that could affect the pressure in the return. I don't know how hot Magnaclean filter housing gets but installation there puts it right next to fan inside the boiler ......


    The Filter housing itself had a 100mm diameter so could be very difficult to reach
    and detach for servicing ....
     
  6. Mottie

    Mottie

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    Looking at your dimensions, I would imagine you could fit a Fernox TF1 Omega mag filter in the pipe run between the boiler and ceiling fairly easily.
     
  7. ianmcd

    ianmcd

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    You can use any 130 pump you want, the 130 refers to the length of the pump housing 130mm, you used to get 180mm pumps but not any more all domestic pumps are 130, as for the filter in a new install as close to the boiler on the return on a new installation is recommended, on yours anywhere on the return will do, if it was my own home would I install one ? would I fook , but fill your boots, not sure what you expect it to do to be honest
     
  8. cooa99

    cooa99

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    @Mottie , that sort of looks like it might work by keeping the fern filter body tilted at 45°. Still awkward servicing because the body will have to be rotated horizontally to remove the magnet at the top.

    Why do manufactures state filters are best installed on the return to the boiler?. Only reasons I can possibly think of are (1) Coolest part of the system and magnets operate better, (2) The pressure requirements for the system are not negatively impacted. Any clues?

    @ianmcd, I have gone through using sentinel X400 for 3 weeks, flush, X800 for 4 days , flush and I still think there is still some sludge left in the system. The ageing pump is not as noisy however the last large Double panel radiator downstairs (though hotter) is still not fully hot at the bottom/middle.... even with balancing or shutting off the other Rad. I have taken that Rad off and blasted with a pressure washer but I get the impression there is still more sludge

    The boiler, radiators and some pipework will be removed in about a year so most of my efforts are more or less short term measures to keep the system working efficiently. I would prefer additional measures to further clean the system and radiators if it's possible that I don't need a filter (for my short life system) but I don't know of any stronger product than the sentinel. I am also thinking of getting "Powerflushing Vibrating Hammer , Radiator Sludge Agitator" from ebay and hopping that might work .....
     
  9. Mottie

    Mottie

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    If they were on the flow from the boiler, the particles from the system (rust from rads) would have to go through the boiler to be picked up by the filter.
     
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  11. ianmcd

    ianmcd

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    Do not use X800, you are just asking for trouble
     
  12. cooa99

    cooa99

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    True, completely forgot about that.

    I already used it over 4 days a couple of days ago. Please what issues could arise so I can keep my eyes/ears out for?
     
  13. Gasguru

    Gasguru

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    It kills pumps but given that the Circulating Pump model you have is ancient and were never that great for lasting long you've nothing to loose...just don't run any X800 with a modern pump.
    The water traveling through that old cast iron heat exchanger at a very low velocity and it's almost certain most of the sludge and debris will remain in there.
    Unless you've got problems I wouldn't bother powerflushing etc... there's a lot more to it than seems.
    I guarantee 99% of radiators failing to fully heat up do not require cleaning or powerflushing...the problem is nearly always a weak/undersized pump, poor balancing, let-by on mid-position valves, poor pipework layout etc.
     
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  14. ianmcd

    ianmcd

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    Apart from killing pumps if you have old radiators it pin holes them if they have weak points
     
  15. cooa99

    cooa99

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    ...mmm lots of food for thought. I am going to do another full system drain just to make sure there is no x800 still hanging around. I have had to drain the whole system by opening all the valves on each radiator on the ground floor so clearly I don't have 'a' lowest point. It also just occurred to me that water in boiler/heat exchanger is never drained because the flow and return go in at the top. So any heavy particles sitting in the exchanger won't come out .... unless the boiler itself is also drained at the heat exchanger

    ... While replacing the pump and gate valves, apart from the washers do I need ptfe or compound on the threads at all ?
     
    Last edited: 25 Apr 2021
  16. cooa99

    cooa99

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    I could do with some advice please.

    The large nuts on the 2 gate valves won't shift. The stillson type wrench I have can hardly grip properly especially because of the tight space. I able to undo the smaller nuts but the sections of the pipes going into the gate valves (at top & bottom) won't flex enough for me to get the pump + 2 valves out as one unit. Unfortunately I don't have a blowtorch which I could use to deal with cutting the pipe below .....

    Will using a Dremel to slice the large brass nuts on both gate valves be the way to go?
     
  17. Mottie

    Mottie

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