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

 

[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.

 

[doitmyself]

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.

But even the index rad may need to be throttled to give the required temperature drop if the pump can't be set to do this.

2.5 m/s seems excessive, most books suggest a maximum of 1.5 m/s and preferably only 1 m/s.

Presumably the calculation used to find the index rad for a manifold based system is exactly the same as for a non manifold system.

 

[DirksPlumbing]

But even the index rad may need to be throttled to give the required temperature drop if the pump can't be set to do this.

2.5 m/s seems excessive, most books suggest a maximum of 1.5 m/s and preferably only 1 m/s.

Presumably the calculation used to find the index rad for a manifold based system is exactly the same as for a non manifold system.

In terms of a heating system you are correct. 2.5 m/s is excessive.
Copper is usually specified for 0.5 - 2.5 m/s. But we are looking at this layout at a full load situation.
Once some radiators start shutting down the pressure may increase depending on the pump / bypass valve settings.
Then the flow rates go up and your previous 2+ m/s quickly gets beyond the 2.5 m/s. Noises, water hammers ...
Though I think that these DN6 and below pipes are usually somewhat restricting you never get much over 2.5 m/s anyway.

Yes there can be situations where you want to throttle the index rad. But with the availability of different pipe systems and various pumps with a wide range of settings this becomes rare in domestic situations. In commercial applications you would rather limit the stream via differential pressure control valves very granular.

Mind that most presettable valves only have 4 - 8 settings anyway. And apparently that seems quite sufficient. I still stand to my opinion that in a microbore system I rather live with the limitations instead of even further reducing the flow and fitting a commercial pump. That does not stand for mixed installations.

I do not fit microbore systems but I admit the use of 10mm pipe in existing microbore installations otherwise you bring the system in quite an imbalance.

Manifold systems still have their place (underfloor heating for example). If there were half decent priced normal bore manifolds available at the merchants I possibly would do normal bore manifold systems with MLCP. No joints under the floor. Especially with pipes run in concrete floorings within a corrugated conduit you just pull the old pipe out and the new one in (if not to long or to sharp bends or crushed -> workmanship). Though you need a place for the manifold in a cupboard or so.

 

[DirksPlumbing]

Ah, "rather rare" is maybe not so right. One thing that drives me mad is that there are still a lot heat only boilers sold that do not have the ability to differentiate between a CH demand and a HW demand. Then you have to set up the flow temperature in order to satisfy the cylinder rather the heating system.

I wonder how that could slip through ErP regulations.

 

[Bennachie]

For those interested I have refitted my 28 year old HEAD unit to my new valve.....(interim as I am busy and do not want to drain down in the cold weather) ............. and the noise whilst not totally erdicated IS much reduced. So for all us conspiracy theorists out there Honeywell HAVE hanged something ( or their tolerances are not what they once were.......)

 

[doitmyself]

In terms of a heating system you are correct. 2.5 m/s is excessive.
Copper is usually specified for 0.5 - 2.5 m/s. But we are looking at this layout at a full load situation.
Once some radiators start shutting down the pressure may increase depending on the pump / bypass valve settings.
Then the flow rates go up and your previous 2+ m/s quickly gets beyond the 2.5 m/s.

But, with most pumps, if the pressure increases then the flow rate, and consequently the velocity, reduces.

 

[johnthom]

For those interested I have refitted my 28 year old HEAD unit to my new valve.....(interim as I am busy and do not want to drain down in the cold weather) ............. and the noise whilst not totally erdicated IS much reduced. So for all us conspiracy theorists out there Honeywell HAVE hanged something ( or their tolerances are not what they once were.......)

I wonder if it's just the weaker spring in the old head leading to more gentle closing when falling back to DHW Only. Is there a noise when the valve is crossing the other way onto CH Only?

 

[Bennachie]

No. Silent apart from DHW only required. I see from a US blogger tht the problem is widespread in USA and that Honeywell 'are not aware of it'!!!! All sorts of cunning solutions over there but not available here without exhorbitant shipping fees. Its because as soon as the motor in the valve is 'released' by the micro switch the pump starts and slams the ball into its seat. There needs to be a delay between the de-energising of the stalled motor and the external power feed from the tank stat...........

or

as I think may case is with the old head, the clearances are reduced in the pivot providing a more damped action.

Internet trawling provides a lot of information.............

 

[ShaunCorbs]

No. Silent apart from DHW only required. I see from a US blogger tht the problem is widespread in USA and that Honeywell 'are not aware of it'!!!! All sorts of cunning solutions over there but not available here without exhorbitant shipping fees. Its because as soon as the motor in the valve is 'released' by the micro switch the pump starts and slams the ball into its seat. There needs to be a delay between the de-energising of the stalled motor and the external power feed from the tank stat...........

or

as I think may case is with the old head, the clearances are reduced in the pivot providing a more damped action.

Internet trawling provides a lot of information.............

be easier to change the valve to a different brand tbh drayton are fine no noise

 

[Bennachie]

Trying to avoid draining down until the spring when there are other bits of pipework to do.
Trying to save the inhibitor...............:8:

 

[DirksPlumbing]

But, with most pumps, if the pressure increases then the flow rate, and consequently the velocity, reduces.

Right but wrong. The overall flow rate reduces because there are less easy paths to go. But in the remaining easy paths the flow rate increases because off the higher pressure. Possibly have a look at the Danfoss RA DV valves. They have been invented to overcome exactly this problematic.

 

[DirksPlumbing]

No. Silent apart from DHW only required. I see from a US blogger tht the problem is widespread in USA and that Honeywell 'are not aware of it'!!!! [SNIP].

At current I am under the impression that Honeywell is having difficulties to recognize problems in all areas. Since 2013 I continuously have to change Honeywell parts that are either still under warranty or just out of warranty.

A lot of them I have done on my own accounts including the parts. "Not amused" is a good description. I love my profession but not to this degree.

 

[DirksPlumbing]

That valve had just been 13 month fitted. Yes I had modified it (top right to provide a temporary demand signal) but after it struck. All it was switching was a new Worcester Camray and an Alphal 2L 15/50.

CM9x7 is another soar spot. And I am not talking about the occasional random flame symbol not matching the demand signal.

 

[Bennachie]

Interesting my Honeywell prog thermostat often says it is calling but nothing happens.........
On delay timer is the answer to 'knocking balls', (snigger :wacko but why something that is available easily in the US for approx $5 delivered (to US address) should sell for £25 to £30 in the UK is beyond me. Finding a supplier is hard enough! Sadly most US wont ship to UK unless many dollars changes hands, so if anyone knows a source of TD69 solid state, on-delay timers in the UK at reasonable price..........................?

 

[ShaunCorbs]

Low Cost Adjustable Solid State Timer, Delay-on-Make, Delay-on-Break

but have a word with these guys first

RS Components | Electronic and Electrical Components

 

[Bennachie]

Thanks shaun RS was my first port of call but £30 if they have one. They have relays but not in-series timers

They are $5 stateside, on supplier offering 5 for $10! Rip off Britain or what?

Omega £30!!! with delivery and a 5 week lead time!!

I don't understand, we must use them over here somewhere......