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?
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?
Would these be ok either side of the pump? https://www.screwfix.com/p/ball-type-pump-valve-28mm-x-1/9646v
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
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.
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.
That is the first I have seen Peglers pump valves in 28mm size. Wasn’t sure they existed and didn’t find them online in a quick search. Very good valves
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.
dont throw away your vibrating pump it will have some use think about the coldest winters day and your new pump fails.
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.
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
Thanks again everyone, some really good advice. Will certainly consider the Grundfos Alpha 2L before making a final decision.