Grundfos two-speed Super 4 is dying - Help!

Can anybody give me some advice about my central heating pump - It's on it's last legs & will now only run on it's high speed setting. It makes an awful noise - clattering and "Kettling" and has simply stopped on a couple of occasions over the last few days. It is a Grundfos two-speed Super 4 pump, type: 4.50/130, 2500rpm,105W, class 4, if that helps. I think it's a fairly old model. If it needs replacing, would a UPS 15/50 or 15/60 be suitable? Any advice v. gratefully received - s'not all that warm, these days!

Clearly your pump bearings are very worn and the extra resistance probably means it will only work at the maximum setting.

Unless you have more than about 10 rads then a 15-50 on the setting 2 will easily suffice.

A new pump will cost less to buy than filling a car with petrol.

Tony

Tony,
Many thanks for taking the time to reply to my query, and for your advice. I'll try to obtain a 15-50, as you suggest, and I'll call in a professional to fit it - peace of mind is worth the price.
Cheers,
Tim.