Grundfos Alpha2

[Glasuni03]

Hi, looking for advice from you guys, the plumbing experts. Ever since my old Grundfos central heating pump (blue in colour) packed in over 9 months ago the local plumber replaced with the grundfos Alpha 2. It's been a nightmare truth be told!

the radiators have been banging which I've been told is down to expansion which I don't accept now as it never stops when the heating is on? There is the odd time that constant banging at the trv side in one radiator for 20-30 seconds

The alpha2 has an auto adapt which I believe works on the basis of how much hot water required it automatically increases the pressure. Only problem is when on auto adapt the rads downstairs and one in the bathroom doesn't heat?

When the pump is set at rating 2 it heats the house but we get the awful noises.

when hot water and central heating on at same time rads downstairs get hot at top but stone cold at bottom

even when the try says rad is not required to heat up due to temp in the room there is the banging noise/ticking noise when stone cold? Is this normal too?

Having looked at the Grundfos website it says that the Alpha2 shouldn't be fitted on trv systems on setting 2. Why might auto adapt not be working? I have had the system recently power flushed and this is driving us mad

any feedback somebody could offer I would be very grateful

 

[lame plumber]

trv flow probably one way only and set up wrong way, the pump needs to be set up as per manual, and system may need rebalancing.

 

[Glasuni03]

Trvs are the danfos bi-directional (all on flow with exception of 1)

Is it best to swap this pump out for the blue danios model as it never made all these noises

why doesn't the pump give both hot water and all rad heat when on at same time?

 

[hammers4spanner]

pump correct size?

 

[SafeGasInstall]

I have exactly the same expectation just like you , gf2 will not last long on the market :

due to many systems installed correctly or builders plumbers adding on more radiators without upsizing the flow and return on the central heating

 

[Ray Stafford]

I sometimes wonder if Alpha pumps are just a bit too clever for their own good, particularly when they are fitted on old systems.

 

[Glasuni03]

Thanks for feedback guys. How can these problems be resolved?

 

[Rickster123]

I've got a few non alpha pumps in the garage saved for a rainy day.

 

[SafeGasInstall]

new old type pump or repipe ch system , i know your answer before asking my question 🙂 lol

 

[hammers4spanner]

stick a combi in hahahaha

 

[Rickster123]

stick a combi in hahahaha

42kw!

 

[Howsie]

Grundfoss assume that your systems has been installed and modified properly, sadly this is rarely the case anymore as everyone's and plumber/heating engineer. Sadly, very few really are.

 

[turnpin]

Technology is the future until it go`s wrong then we all look to the past and remenis about the good old days ....lol regards Turnpin

 

[Billy Bob Bob]

Hi, looking for advice from you guys, the plumbing experts. Ever since my old Grundfos central heating pump (blue in colour) packed in over 9 months ago the local plumber replaced with the grundfos Alpha 2. It's been a nightmare truth be told!

the radiators have been banging which I've been told is down to expansion which I don't accept now as it never stops when the heating is on? There is the odd time that constant banging at the trv side in one radiator for 20-30 seconds

The alpha2 has an auto adapt which I believe works on the basis of how much hot water required it automatically increases the pressure. Only problem is when on auto adapt the rads downstairs and one in the bathroom doesn't heat?

When the pump is set at rating 2 it heats the house but we get the awful noises.

when hot water and central heating on at same time rads downstairs get hot at top but stone cold at bottom

even when the try says rad is not required to heat up due to temp in the room there is the banging noise/ticking noise when stone cold? Is this normal too?

Having looked at the Grundfos website it says that the Alpha2 shouldn't be fitted on trv systems on setting 2. Why might auto adapt not be working? I have had the system recently power flushed and this is driving us mad

any feedback somebody could offer I would be very grateful

GRUNDFOS WERE NEVER BLUE your old one was a SMC ot MYSON as said fit a new old stock non weird pump

 

[Rickster123]

GRUNDFOS WERE NEVER BLUE your old one was a SMC ot MYSON as said fit a new old stock non weird pump

 

[tamz]

Might have been the BG version of the grundfos Mark.
Has the new pump been fitted the correct way round?
If the tr's weren't rattling before an alpha2 shouldn't make any difference.They make the noise because the water is going through the valve the wrong way.
Firstly, check the pump is pointing the correct way.
If it is, remove the trv heads and check the selector switch is set right on each valve.
Get your system properly balanced
The alpha can be set to constant speed the same as your old pump if it really needs to be.

 

[Billy Bob Bob]

View attachment 15177

been saving that one haven't you LOL anyway that needs a magnaclean allegedly

 

[Rickster123]

been saving that one haven't you LOL anyway that needs a magnaclean allegedly

I had to search and search! Damn you british gas!

 

[Ermintrude]

GRUNDFOS WERE NEVER BLUE your old one was a SMC ot MYSON as said fit a new old stock non weird pump

BG and scot power are blue, the alpha is modulating up and down. Your trv heads are weak . I.e the pump in its initial high power output are lifting the valves of seat.... Pun then thinks it's got a massive job on its hands so goes at full grunt hence noise. Easy way to test this is open your bypass fully.... Noise will be gone and boiler will hit temp very quickly, system will remain cold. Just gradually turn bypass down until it's all toasty? Or rib out alph stick it on eBay ad buy a wilo one!

 

[snowhead]

I had to search and search! Damn you british gas!

30 seconds to find this;
British Gas Central Heating Pump by Grundfos | eBay