Honeywell v4073a valve noise

[Bennachie]

Hello!

The aforementioned mid position valve has been replaced on an open vented, Y plan system with 22mm primaries and 8mm feeds to radiators from manifolds (I know). The system is clean and all radiators are new. Heating and DHW are fine, both work as required and provide required heat. However, if CH and DHW are on together, there is a significant 'thunk' from the valve when DHW is satisfied. This did not happen with the previous Honeywell valve (still going strong after 28 years) which was changed out as it seemed like the right thing to do as the system was being upgraded. GSR man fitted a new boiler (GW HSX) and a replacement Grundfos Alpha 2L 15-60 Pump (which, incidentally is not intelligent enough) to replace the 28 year old 15-50 which, was not quite man enough for the 28 year old Glow Worm Fuel Saver when the thermostat was turned right up.......

There is no 'balancing valve' in the DHW circuit, which is completely 22mm pipe.

I am assuming that the clunk is caused by unrestricted flow through the 22mm heating pipes slamming the honeywell ball closed as there is much more resistance in the heating circuit than there is in the DHW.

My question is therefore, is there a simple solution to this problem?
Will a valve swap solve the issue?
Should there be a 'balance' on the dhw circuit?

Many thanks

 

[Bennachie]

A week gone and loads of views but no one has come across this before?


Hmm.................

 

[ShaunCorbs]

there should be a bypass fitted, but haven't come across a mv that has a loud clunk as the parts inside eg the decider for hot water or heating or both is rubber so shouldnt clunk

bit of a long shot but could you post a vid up of it in clunk mode ?

 

[townfanjon]

Sorry I have only just seen this, as Shaun says .... Bypass is needed , the zone valves close slowly or should do .

 

[Bennachie]

Any idea why it should do it with a new valve but not with the old one? It is definitely slamming shut as you can make it do it by moving the valve manually off the seat and releasing. It also does it to a lesser degree with the pump not running and call for DHW as the valve is de-energised and springs back to DHW only..............

Many thanks to you two for replying, I was beginning to give up hope.........

 

[ShaunCorbs]

Any idea why it should do it with a new valve but not with the old one? It is definitely slamming shut as you can make it do it by moving the valve manually off the seat and releasing. It also does it to a lesser degree with the pump not running and call for DHW as the valve is de-energised and springs back to DHW only..............

Many thanks to you two for replying, I was beginning to give up hope.........

busy week

i see so its when the pump is still running and the motorized valve shuts eg no call for heating or hot water?

 

[townfanjon]

The odd post does go missing but now its back on the 'new posts' loads will see it lol

 

[doitmyself]

However, if CH and DHW are on together, there is a significant 'thunk' from the valve when DHW is satisfied. ...a replacement Grundfos Alpha 2L 15-60 Pump (which, incidentally is not intelligent enough)

So the clunk occurs when the valve goes from mid-position (CH and HW) to CH only? Do you get a clunk when CH is called by itself? (The valve needs to be set to the HW only position to check this: set timer to HW on; turn cylinder stat down; turn the complete system off and back on. Then turn CH on and room stat up.)

What setting is the Alpha pump on and why do you say it's not intelligent enough?

Did the installer balance the system after installing the new boiler and pump?

Which versions of the Fuelsaver and HSX?

 

[Bennachie]

System is balanced (I believe)
Was Fuelsaver 45ff is now Ultracom HSX18

1.
No CH, No DHW, no pump. CH is timed to come on. There is a slight, but noticable thunk as the spring return is released then pump and boiler fires.

2.
If both CH and DHW are called for, (or if one joins the other) the pump runs, boiler fires etc., etc. when DHW is satisfied a louder thunk happens as the valve is (I assume) slammed shut.

I acquired another valve body and have been comparing it with my old one and there are differences, no doubt in an effort to save money. However, the action of sealing the ball seems slightly different on the older one by allowing a progressive introduction of the surface of the ball to the metal seat. This could of course simply be the action of age.......

Alpha 2L 15-60 set on 3 as 2 is not man enough and causes kettling noises and none of the 'clever' PP settings prevent kettle.

 

[DirksPlumbing]

There would be an easy solution: get a balancing valve fitted.

The thud occurs by a high mass of water circulating at a high speed and suddenly getting stopped. 1 liter of water is 1kg mass. Water is non compressible.

The Alpha 2L is intelligent but unfortunately the design of the pipework was not at the same level. This pump can do a lot of things. But what you are asking for, you might be better off with a half inch Centerbrand miracle.

Sorry, had to do that . You need to slow down the flow of the coil to match the resistance of the rest of the system. As you use the pump in an uncontrolled mode you should have as well the aforementioned automatic bypass. This major difference in flow speed will cause further problems once the system needs to heat the house. During DHW heat up there will be likely little to no heat for the radiators und an unnecessary high return temperature causing cavitation and efficiency loss.

If the boiler "kettles" it simply has more heat available than it can get rid off. A half decent modern boiler will quickly modulate down. If there is cavitation even on low load then its time to call someone qualified. I had one case where a 40kW heat only boiler had been fitted to a brand new house. When I calculated the rads, there were roughly 10kW load. The boiler could modulate down to 12kW. I think that is said enough.

 

[DirksPlumbing]

By the way, at what flow temperature do you run your boiler? A lower temperature means less temperature on overshooting. But of course you need at least cylinder temperature +5K.

 

[DirksPlumbing]

System is balanced (I believe)
[Snip].

Please do correct yourself here. I hope the system is not balanced. To squeeze the water through DN6 and then still throttle the flow even further down does not make the slightest sense at all. Unless the system is not working anyway and you try to provide the customer with a solution until the problem is fixed.

Rule of thumb: do not balance microbore. Grundfos does do great webinars and courses regarding balancing for free.

The TRVs are the best balancing in such a system. All lock shields fully open.

 

[DirksPlumbing]

I assume the old setup had the pump switched by demand rather into the pump port on the boiler?

 

[Bennachie]

Demand

Thanks for your help. System runs at 68 degrees. House is warm, all rads are hot and DHW heats rapidly. Rads remain hot when both DHW and CH are on. System appears effective apart from the hammer on valve closing.
To alleviate the hammer I have programmed separate session times for CH and DHW temporarily.

 

[DirksPlumbing]

If you got the time just compare the return temperatures of the CH and the DHW on a normal system run. Your return temperature determines how much gain you have from condensation.

Of course not solely but mainly. You will struggle to cool your flue gases to 60 degree if you have 61 degree return.

 

[DirksPlumbing]

Just another thought, what is your system pressure?

 

[Bennachie]

Open system...............

 

[DirksPlumbing]

System is balanced (I believe)
Was Fuelsaver 45ff is now Ultracom HSX18
[snip]

A Glow-worm Ultracom HSX18 then? Can you post the GC Number? :rolleyes2:

 

[Bennachie]

My error, 18 HXI

 

[doitmyself]

To squeeze the water through DN6 and then still throttle the flow even further down does not make the slightest sense at all.

Who said anything about squeezing water through pipe? The purpose of balancing is to get the correct flow through every radiator. The fact that each radiator is fed by a separate pipe helps but a 500W rad still needs half the flow rate of a 1kW rad.

Grundfos does do great webinars and courses regarding balancing for free.

Links please.

The TRVs are the best balancing in such a system. All lock shields fully open.

I doubt if Drayton and Honeywell would agree with you.

 

[DirksPlumbing]

Who said anything about squeezing water through pipe? The purpose of balancing is to get the correct flow through every radiator. The fact that each radiator is fed by a separate pipe helps but a 500W rad still needs half the flow rate of a 1kW rad.

I doubt if Drayton and Honeywell would agree with you.

Water has roughly 1.163 Wh/kg/K and 1kg/l.

At DeltaT 10K that is 11.63 Wh/l.

That gives you 43 l/h.

DN6 has 0.028 l/m. Resulting in 0.42 m/s.

But to KISS it: 500W / (11Wh/l *3600) = 0.0126 l/s.

My flow resistance table goes up to 0.025 kg/s for DN6.

Meaning your comparably tiny rad of 6x6 K2 will result in > 0.566 m head per meter.
At a 5m distance from your manifold this is > 5.66m head.

Or in other words, to use this radiator as per design it needs a separate Alpha2L 15/50 for itself.

I am not saying it does not get heat as the resistance per meter drops quickly. Are you sure that Drayton and Honeywell will tell me that physics are not valid for plumbers?

As for the balancing I have to apologise. Grundfos Ecademy does not provide these courses for UK.

 

[DirksPlumbing]

It was Danfoss E-Learning. http://learning.danfoss.com/NR/rdon...earningHeatingCourseCatalogue_UK_05082014.pdf

 

[DirksPlumbing]

As for the correct flow on a microbore system you will end up with a great mixture of temperature spreads as you cannot get more than the pipes will deliver. How that could be correct, I do not know. But it definitely will not be balanced.

Glow-worm specifies a maximum spread of 20K in some manuals. On lower temperature specs (higher efficiencies) you usually design the 10K only anyway.

Gone are the days of 90/70/20 for most gas appliances.

 

[Bennachie]

So, Dirks, what setting should my 'intelligent' pump be on? The boiler requires 780 l/hr min if I remember correctly. This is all doing my head in.
Dodgy valve emits a dull, damped, rubber thunk even when no pump running and just the spring return to DHW only.........

 

[DirksPlumbing]

I have noticed I had mixed up DN6 calculations and 6mm copper pipe resistances.

What the pump should be set to? Honestly I do not know. But typically the variable pressure modes do not work all to well on microbore systems. Is your pump wired into the boiler pump port? There are so many things I do not know about this system, how could I be able to say this or that?

It is indeed mysterious how this valve can cause so much noise even when the pump does not even run. Change the valve, fit the automatic bypass and a balancing valve and lets see.

 

[DirksPlumbing]

Grundfos Product Center

This is roughly the same curve as on the Alpha 2L 15/60.

 

[DirksPlumbing]

As you can see, the high constant pressure setting limits to 4.5m head and the lower constant pressure setting to 3m head.

 

[Bennachie]

Thanks for your time....and sage words. It is appreciated.
I shall go back to basics and work everything out.
The valve will get changed soon and the bypass will go in.
I'll let you know.

It is weird that it thunks even just on spring pressure. I have a theory about it but it is just that, concerning the seating of the ball within the valve. I think the newer ones contact all of the seat immediately whereas the older ones contact the periphery initially then settle onto the seat, thus giving a 'gentler' shut off.

Trawling the net has brought up a number of similar threads concerning Honeywell valves in particular making this noise, so..........................hey ho.

Constant pressure setting is ok for an open vent system I assume
Thanks again.

 

[doitmyself]

I have noticed I had mixed up DN6 calculations and 6mm copper pipe resistances.

Can't see what relevance DN6 and 6mm has? The OP has 8mm pipe -presumably copper considering the age of the installation - approx 28 years.

A 500W rad with a 10K differential will require 0.012 kg/sec so 8mm pipe will have a resistance of approx 0.033 metres/metre length, i.e, 0.3m for a rad 5m from the manifold. The water velocity would be only 0.3 metres/sec, which is just about acceptable if sludge deposits are to be avoided.

 

[DirksPlumbing]

Can't see what relevance DN6 and 6mm has? The OP has 8mm pipe -presumably copper considering the age of the installation - approx 28 years.

A 500W rad with a 10K differential will require 0.012 kg/sec so 8mm pipe will have a resistance of approx 0.033 metres/metre length, i.e, 0.3m for a rad 5m from the manifold. The water velocity would be only 0.3 metres/sec, which is just about acceptable if sludge deposits are to be avoided.

Okay, given a property of 28 years with 3 bedrooms, one bath, one living room, a hall and a utility. That's 7 to 8 rads. How many of them are likely to be 6x4 P+?

Thinking about 18kW (the boiler) then that would be an interesting sight of ~30 radiators of 500W throughout the house .

DN6 is "diamètre nominal" and 8mm copper pipe has 6.4 mm and is very close to DN6. By latest once you got an 0.2mm oxide layer inside it definitely is.
And the 10mm plastic pipes are playing in the same league if at all.

On balancing your worst radiator determines the settings for all others (logically as you can only throttle). This may be your 6x16 K2 at ~2800W with 0.068 l/sec and roughly 12m microbore 8mm. That is a gently 2.1 m/sec and therefore a good speed well under 2.5 m/sec.
Looking in the table the pipe resistance is: oops , we do not know as it's outwith the specs in accordance to the table. But lets assume 0.4 meter head per meter x 12 its 4.8m head.
Now the boiler requires a minimum flow of 773.86 l/min. Adding 1.4 meter head for the boiler as per MI and another meter for the rest of the pipework and fittings we are now at 7.2 meter head loss at ~774 l/min. You need a Magna 25/80 to allow that system to run half decent once it's balanced.

I am sure the customer will be totally happy about the savings he is going to acquire after the pump and installation cost (~1k?) and the rise in electricity costs. Grundfos estimates "only" 68.2 W for the required setting.

And after a while the customer will not even notice the valve noises anymore as he got used to it. Hopefully. Would a pump like this push 22mm 2port or diverter valves open? But hey you won't need an automatic bypass then.

 

[DirksPlumbing]

[snip]
Constant pressure setting is ok for an open vent system I assume
Thanks again.

When fitting an automatic bypass Grundfos used to insist in using the constant pressure settings. The variable settings alter the pressure and make it almost impossible to find a suitable setting for the bypass.

I find this "new" requirement to fit an automatic bypass, no matter what the system design is, contradictive to the attempt to save energy as it prevents the use of the most energy saving settings on the pump. Though in many cases it can help to lower the return temperature and therefore increase the efficiency.

 

[DirksPlumbing]

Regarding the design quality of the newer Honeywell gear I made similar observations. Before 2013 I had barely any replacements. Within the last year I had to replace a lot more and all were 2013 and after.
I started looking at the Horstmann gear but can not say to much about the longevity. Though their (2/)3/4 channel timers are without alternative and I had no trouble with them yet.

 

[Bennachie]

Thanks Dirksplumbing. All very helpful, informative and interesting.

Some I do not understand though. How does one arrive at the velocity figure for the speed of water in the pipe?
I understand the resistance calculations but the speed escapes me.
Also when working out resistance do you add figures for fittings and rad valves? I assume they were left out of the last couple of posts for simplicity.

Thanks again for your time.

 

[DirksPlumbing]

You have to apologise if I am not using the best terminology as I am not a native english speaker.

That is simple maths. Pipes are round (or are supposed to be) and consist of some type of material or mixture of materials. This material has a certain thickness (the wall thickness). Lets take a 15mm copper pipe. It has 1mm wall thickness all the way round. This makes the internal diameter 13mm.

Millimeter is not very handy for calculating volumes as we are typically using liters. Decimeter makes more sense as 1dm * 1dm * 1dm = 1dm^3 = 1l.
One decimeter has 100 millimeter. Our 15mm copper pipe has an internal diameter of 0.13dm.

The surface of a circle is pi / 4 * diameter^2. Thus gives us roughly 0.01327dm^2 for our copper pipe. 1 meter has 10 decimeter.
That gives us 0.1327dm^3 or 0.1327 liter / meter pipe.

If I want to pass 0.1327 liters per second through this pipe then the water has moved exactly 1 meter and as this happened in one second we know now that the water has been moving that one meter in one second (1 meter per second).

Do I want to pass 0.2654 liters per second (double figure) through the pipe then the speed doubles as well (2 meter per second).

x liter/second / y liter/meter = v in meter/second

Yes in the previous calculation I just threw a meter of resistance in for the rest of the fittings and pipework. As you would have needed to adjust the lock shield (no manufacturer I know manufactures presettable valves that would allow this kind of adjustment) hence you can forget about the lockshield as it is to be set to what ever additional resistance will be needed.
Except of course for your worst radiator, there it needs calculated as fully open.

 

[Bennachie]

Thanks. No apologies require re native language. Your English grammar and sentence construction are fine; and significantly better than my flimsy grasp of 'foreign' languages, which is limited to spoken (poorly spoken) French and a little Italian and the ability to read French.