Altecnic Eres automatic bypass valve correct setting number

[big john hog]

Dear Sirs,

I was wondering if someone could possibly inform me of the correct setting for my Altecnic Eres automatic bypass valve numbered from 0.1-0.5 bar.I have a conventional Ideal ff 350 Classic boiler .The central heating pump is a Grundfoss ups 3.15--50/65 set to speed setting number two at a constant rate with two leds permanently lit I consulted the installation manual for the boiler and have found the max static water head to be 30.5 (100).Min static water head to be 0.45 (1.5) m(ft).Water flow 19.0 l/min at a rate of 250 gal/h.
I am having problems transposing this data to the Altecnic Graphs.Can someone do this for me please as I am confused.Many thanks

 

[John.g]

Where is the ABV located in relation to the pump, the further away from the pump the better.
Do you want the ABV to open when the boiler shuts off ie all zone valves shut? Do you TRVs fitted to the radiators?.

 

[big john hog]

Where is the ABV located in relation to the pump, the further away from the pump the better.
Do you want the ABV to open when the boiler shuts off ie all zone valves shut? Do you TRVs fitted to the radiators?.

Dear john.g:

The ABV is located in the airing cupboard next to the Grundfoss pump and hot water cylinder on first floor. Boiler on ground floor in utility room.I have fourteen rads with eight TRV valves always kept fully open so house zones are always hot .I just control heat setting on thermostat in hall set to 23 degrees.Hope this is of some help to you .I have set ABV to position three just as a best guess.I have 10mm small bore plumbing to rads .ABV is 22mm on return pipe

 

[John.g]

Presume ABV is on the discharge side of pump and is only needed when the rad stat (or programmer) shuts the boiler down. The problem with setting up the ABV with all modern pumps is that the pump curves have no real CC (constant curve) settings, as they keep a practically constant head in both CC (and CP) modes, see curves below, you have, in effect 5 CP settings on that pump and 2 PP settings. Can you also tell me exactly what two LEDs are permanently lit and their colours to identify which mode you have set the pump to and might be able to make a recommendation based on this or suggest a different pump mode.

 

[big john hog]

Presume ABV is on the discharge side of pump and is only needed when the rad stat (or programmer) shuts the boiler down. The problem with setting up the ABV with all modern pumps is that the pump curves have no real CC (constant curve) settings, as they keep a practically constant head in both CC (and CP) modes, see curves below, you have, in effect 5 CP settings on that pump and 2 PP settings. Can you also tell me exactly what two LEDs are permanently lit and their colours to identify which mode you have set the pump to and might be able to make a recommendation based on this or suggest a different pump mode.

View attachment 66502

View attachment 66501

 

[big john hog]

Dear John.g:

The ABV is located on the return 22mm pipe below Grundfoss pump is that the discharge side .I see the problem with these modern pumps .I have examined pump and instructions.The setting is II Constant Curve II ,with green and yellow LED's permanetly lit.
Prior to this new numbered ABV valve an old fashioned valve with a white plastic cap was installed.Would that have been an old traditional gate valve which was just wound in and out accordingly I hope this has been of help to you

 

[John.g]

You can see that CC2 gives a constant head of 5.2M up to a flowrate of 1.1M3/hr, 18.3LPM and its unlikely that your system will be running at this level. CC1 will give 4.2M constant head up to a flowrate of 0.7M3/hr, 12LPM and the starts falling off. If your system flowrate is say 1.0M3/hr, 16.7LPM then the pump head will be 3.6M and much easier to get some form of control with the ABV but of course your system may not be happy running on CC1.
Which ever curve you finally settle on, start with the ABV at its highest indexed setting (so closed), shut off one valve (or TRV) on all rads except say one or two required to keep the boiler running at minimum output then slowly reduce the ABV setting until the downstream pipe just starts getting hot then turn back the setting say a 1/4 of a turn, reopen all shut valves. A manual valve would give better control because all these A rated pumps for some inexplicable reason best know only to themselves do not give true CC operation and a ABV will have to be set up to bypass water at all times except in your case IF you can run in CC1 where the flow requirement may well result in a reduced head resulting in the ABV closed except on pump overrun.

If you only need the ABV to open on boiler shutdown/pump overrun I can suggest another method but needs a normally open motorized valve and a bit of electrical wiring.
Can you post a phot of the ABV, Pump & pipework.

 

[big john hog]

Dear John,g:

Many thanks for your expert technical knowledge and taking the time to compare the pump speeds and curves for me.I have followed your instructions and the ABV only required turning out from closed about one and a half turns to feel the downstream pipe to start getting hot.I plan on winding out one full turn from this So two and a half turns. from closed position to allow for any further heating of the pipe
The automatic bypass valve is now set to position five.Many thanks once again problem solved

 

[John.g]

Are you sure you have turned it the correct way after feeling the pipe getting hot?, you turn it back a touch opposite to the way you turned it to get it to open.

 

[big john hog]

Dear John,
Well spotted .I will correct my mistake and wind it back the quarter turn from direction I wound it out. as you initially said to do. Is this now correct making the white tab washer indicate setting to just below position five.

 

[John.g]

The setting index is just a guide, this is why you set it up "practically", you be better off starting from scratch again as its important to get it just right especially with little or no change in the pump head to play around with. So maybe shut it again for a hour or so to allow the pipe to cool down, shut off most of your rads, (did you do this originally?) adjust setting until pipe just starts to get hot then back off no more than 1/2 turn, 1/4 might be better, re open rads.

 

[big john hog]

Dear John,

I think that your advice is best to start from scratch when cold. I may well contact the local plumber and ask him to set it up for me.Many thanks once again for your expert help

 

[John.g]

No need for your plumber, , just wind the ABV shut and allow the pipe to cool down then just repeat what you have done earlier.

 

[big john hog]

Dear John,g:

Sounds like a good idea just let it cool down and repeat process

 

[John.g]

Yes, just take your time, the only downside of excessive by pass is that it raises the boiler return temperature and you lose a bit of efficiency.