Setting Honeywell DU145 Auto Bypass Valve

[chris watkins]

Oh I forgot, the 15 mm and 22 mm gate valve are exactly the same, crap for balancing two turns open and they are fully open.

One other very important point on domestic, the coil in the cylinder if you have one offers the lowest resistance to flow of any other part of the system, therefore when you balance the system on a 3 port valve with the ball in the middle you must go and balance the coil along with the rads, I would start with the 15 mm balancing valve off the coil 1.5 turns open and work up from that.

I you struggle to get a 10 Deg C drop across your rads then you have stretched you pipe sizes to the limit or you have got silly long runs that are using up the head of the pump.

And remember this, you use a high head pump it cost more to run than a normal pump, if you have the speed set up to 3 then the life time running cost is high, I remember when all system were all gravity, Doh, just about and two pipe system just invented.

Tony

Hi Tony
The plumbing industry along with technology never stands still, I suppose that's why we love it so.
We now balance to achieve 20 deg C across F&R, don't fit balancing valves to the cylinder primary's (well I don't) due to the 25-30mins heat-up of modern cylinders & have the hot water on first then go over to any heating.
The use of the new generation of circulators such as this Alpha 2 both with it's auto variable speed settings (& energy saving motor) means we can have the speed 3 only when it's needed & lower ones when not, saving a bit of money & system noise.
The one thing that has not changed & won't ever is the need to understand what & why we have to do to make these systems work, just like balancing the system, the flow meters may help but you have to know what the flow rate should be in the first place.

 

[chris watkins]

Yep it's set to auto adapt. Is that ok?

Ant

the attached from Grundfos should help you antsals.
View attachment BypassCommissioningAlpha2or2L.pdf

 

[happyflyer]

Hi Tony
The plumbing industry along with technology never stands still, I suppose that's why we love it so.
We now balance to achieve 20 deg C across F&R, don't fit balancing valves to the cylinder primary's (well I don't) due to the 25-30mins heat-up of modern cylinders & have the hot water on first then go over to any heating.
The use of the new generation of circulators such as this Alpha 2 both with it's auto variable speed (& energy saving motor) means we can have the speed 3 only when it's needed & lower ones when not, saving a bit of money.
The one thing that has not changed & won't ever is the need to understand what & why we have to do to make these systems work, just like balancing the system, the flow meters may help but you have to know what the flow rate should be in the first place.

Can you let me have a wiring diagram for the Alpha 2 pumps, I do know what you are on about, the flow rates are simple, I am off shooting this morning as all plumbers do, i will be back Chris


Tony

 

[chris watkins]

Can you let me have a wiring diagram for the Alpha 2 pumps, I do know what you are on about, the flow rates are simple, I am off shooting this morning as all plumbers do, i will be back Chris


Tony

I am starting to run now, how much start do I get Tony ?

 

[doitmyself]

I have an Ideal FF360 Classic boiler

The Installation Instructions say that you only need an ABV if you have separate zone valves for the heating and hot water. If you have a mid-position valve you do not need an ABV.

Building Regs say that you only need an ABV if the boiler manufacturer says you do.

 

[chris watkins]

The Installation Instructions say that you only need an ABV if you have separate zone valves for the heating and hot water. If you have a mid-position valve you do not need an ABV.

Building Regs say that you only need an ABV if the boiler manufacturer says you do.

What if you have to use a auto by-pass to relieve a build up of pressure in the system due to, maybe TRV closing down etc ? nothing to do with the boiler.
It is not always just that the boiler needs an open pathway for pump overrun / overheat.

 

[SafeGasInstall]

Chris isn't the rad that have a two lock shields that is a by pass to ch system the I e near the roomstat

 

[SafeGasInstall]

I e - one

 

[happyflyer]

What if you have to use a auto by-pass to relieve a build up of pressure in the system due to, maybe TRV closing down etc ? nothing to do with the boiler.
It is not always just that the boiler needs an open pathway for pump overrun / overheat.

I don't think anyone who ever wrote a building regulation knows the first thing about buildings let alone water to flow in a low water content boiler, go we what the boiler manufacture says.

Tony

 

[chris watkins]

Chris isn't the rad that have a two lock shields that is a by pass to ch system the I e near the roomstat

Is this rad not balanced ? these rads / towel rails may not provide enough flow rate to keep the pump or the the boiler happy. The (hall) rad has the two lockshields or rather NO TRV so that the rise in temp can cause system to shut down on the room stat, heating "Inta-lock".

 

[SafeGasInstall]

I don't balanced the by pass rad , ONLY if the ch system is really undersized even then this is my verry verry last opt. All I do is open fully lock shields and come back 1/4 turn on each one .
Lets go back to main object here , how do we balance a sh system that has a non A rated pump and has abp but abp lets by under normal operation even when is fully closed ?! I was thinking of this flow regulating valve but have never used one. Any one has fitted one ?

 

[happyflyer]

Hey guys,

It doesn't matter how you do it but at all times water must flow through the low water content heat exchanges on a gas boiler for lots of reasons, as long as the ABV lifts at the right time, it matters not, if its doesn't the boiler will kettle, scale up, trip and blah blah blah, I still think a lot of you leave the spring pressure low JUST TO MAKE SURE it's a comfort blanket. Maybe one day manufacturers will fit and electronic bypass valve which will monitor the pressure both sides of the valve, I commission these every day on commercial systems for pump auto change over.

Tony

If you weren't doing it right now, boilers would be bouncing off the wall. The Alpha 2 is part the way there to this, even if you match the pressure to the load you still ne to ensure there is water going around the boiler at the right rate.