CH system, replace Grundfos, clean and treat?

[Mike7777777]

Hi

Traditional system is 22 years old, Grundfos pump is probably original (at least 15 years old), some noise and vibration from the pump in the cooler weather. It must be three years since I last drained the system, do the cheap cleaning and treatment additives work? One supplier offers 1 litre of cleaner and 1 litre of inhibitor for £11.00.

If the pump is finally dying, is Grundfos the best replacement? Or are there compatible pumps with equivalent or better performance?

Thanks

 

[seco services]

cheap chemicals are no good try stick with fernox, sentinel etc.

as for the pump you won't get better than grundfos.

 

[Mike7777777]

OK, thanks

 

[Agile]

It is a misguided DIY idea that its good to drain a system!

The only time that should be done is if the water is dirty.

There is little point in buying cheap chemicals!

Would you put Tesco oil in a new BMW ?

Tony

 

[Mike7777777]

Missed the intervening posts! How many drains:

Perhaps 5 times in 15 years, 1st drain = to fit TRVs, 2nd = to add additional radiator on ground floor (I can't work quickly enough with frozen pipes!), 3 off because the boiler was "popping". Drained, partially refilled, added cleaner, completed fill. Ran for a couple of weeks, drained, partially refilled, added inhibitor, completed fill. Generally OK for a couple of years afterwards (or more)

Boiler not "popping" at the moment, but system is "knocking", thought it might be a TRV to one rad, but locked off at the exhaust and still vibration. Pump is vibrating, but it's possible that the origin is elsewhere in the system.

If I could be rrrrssseeed, I would change coolant once a year, probably in September, black cr*p that generally appears from system after 3 years or so cannot be conducive to good performance (but why does the coolant in my cars stay as clear as a clear thing after 5 years plus? Running at 100'C+ in iron and aluminium)

 

[Mike7777777]

It is a misguided DIY idea that its good to drain a system!

The only time that should be done is if the water is dirty.

There is little point in buying cheap chemicals!

Would you put Tesco oil in a new BMW ?

Tony

If there's crap in the system then draining is good.

If Tesco sold oil that complied with BMW's spec then yes. Oh alright, it's no, because to buy it would mean that I had visit a Tescos.

I run a TVR on oil bought from Costco, no engine problems .... although there are other problems

 

[Mike7777777]

TrickieDickieBluenose, "popping" boiler has been a recurring problem, but we live in a hard water area (is that relevant?), probably 50% of similar boilers on our small, select estate(?) have been changed, and several hot water tanks.

Our system is on every day, but 80% of the rads are isolated during the summer. System has had inhibitor since 1994 to my knowledge, although it's always possible it has leaked undetected between drains. I really should test the coolant. Water to inhibitor ratio doesn't make much sense to me, 1 litre to 100 for some products, but then 33 litres of anti-freeze wouldn't be cheap!

 

[kevplumb]

i would take what that pratt says with a pinch of salt

 

[Mike7777777]

System drained, Sentinel X400 cleaner added, refilled, bled, noise/vibration problem has gone, although slight vibration of the pump.

I'll leave the cleaner in for a couple of weeks, then drain ,flush (with hose) and add Sentinel X100.

 

[kevplumb]

sounds like a plan fella

 

[seco services]

I'll leave the cleaner in for a couple of weeks, then drain ,flush (with hose) and add Sentinel X100.

something to do christmas day