2 port / mid position valves

[timhoward]

I've been wondering....
There are two estates of bungalows near me, all built together, all with traditional system boilers with tanks and cylinder.
It seems to me that either the valve actuators work for many years, or on some properties they need regular replacement to the point I keep them in stock.
There are about 7 properties where they will routinely go through one in 12-18 months, even if I install genuine Honeywell heads.
Of late I've taken to manually operating the valve about 100 times before putting a new head on, and this does seem to on average extend the life of the head to about 2 years.

Does it seem reasonable to conclude that if they are regularly failing the issue is mechanical friction or limited valve travel and the motor is burning out ?
I'm considering if rather than just changing them I should say we'll try one new head and after that get a plumber in to change the whole valve body.

Any thoughts, similar experiences, wisdom?

 

[ruston]

Any chance there is no inhibitor in and the mechanical side is gunging up and causing the motor to give up the challenge.

 

[timhoward]

Any chance there is no inhibitor in and the mechanical side is gunging up and causing the motor to give up the challenge.

That would certainly be one explanation for the repeated issues. Thanks.

 

[UNG]

I've been wondering....
There are two estates of bungalows near me, all built together, all with traditional system boilers with tanks and cylinder.
It seems to me that either the valve actuators work for many years, or on some properties they need regular replacement to the point I keep them in stock.

Have you checked the wiring is correct I've found some in the past where the wiring was wrong and in certain situations would create problems

There are about 7 properties where they will routinely go through one in 12-18 months, even if I install genuine Honeywell heads.
Of late I've taken to manually operating the valve about 100 times before putting a new head on, and this does seem to on average extend the life of the head to about 2 years.

Do you apply any lubricant to the shaft when you manually operate it? I've found that even the slightest resistance can stop the motor fully operating the valve

Does it seem reasonable to conclude that if they are regularly failing the issue is mechanical friction or limited valve travel and the motor is burning out ?
I'm considering if rather than just changing them I should say we'll try one new head and after that get a plumber in to change the whole valve body.

Any thoughts, similar experiences, wisdom?

The only fix sometimes is to replace the whole valve I've not had to replace many over the years but it has fixed the problem
The only other one I've had is the motor head jamming where the gearbox drives the segment that operates the valve

 

[timhoward]

Thanks, yes I checked the wiring. I normally put a small drop of 3-in-one oil on the shaft. The last one I did required fair effort to turn.

A couple of the customers are understandably getting frustrated and typically ask if there isn't a different/better make or something. I've already explained that changing the whole valve would be required to use a different make.

I'm thinking the best advice for them would be drain down, chemical clean (or even power flush if a water sample merits it), then see how the valve feels, and if stiff change the valve. Obviously adding inhibitor afterwards.

 

[UNG]

Thanks, yes I checked the wiring. I normally put a small drop of 3-in-one oil on the shaft. The last one I did required fair effort to turn.

A couple of the customers are understandably getting frustrated and typically ask if there isn't a different/better make or something. I've already explained that changing the whole valve would be required to use a different make.

I'm thinking the best advice for them would be drain down, chemical clean (or even power flush if a water sample merits it), then see how the valve feels, and if stiff change the valve. Obviously adding inhibitor afterwards.

I use the 3 in 1 oil spray as I find it penetrates better than the 3 in 1 oil

If the valve needs replacing I go for the Drayton valves as Honeywell seem to be living on past reputation

 

[timhoward]

I use the 3 in 1 oil spray as I find it penetrates better than the 3 in 1 oil

If the valve needs replacing I go for the Drayton valves as Honeywell seem to be living on past reputation

Thanks again. I actually changed a Drayton yesterday for first time and it seemed a. I’ve product, in this case I’m sure the mechanical valve itself was to blame.

 

[brianmoooore]

Motor life shouldn't be affected by the valve being hard to operate since the motors are designed to be still powered when stalled against the end stop.
If a mid position valve is in the full heating position when the heating switches off on the programmer, it remains powered and stalled until the next time the water is heated, which can't be good for the motor's life.
I gave up using mid position valves many years ago, using only two port valves since, as this problem doesn't occur with them. I've also changed many mid position set ups to a couple of two ports when replacing valves.

 

[johntheo]

I've been wondering....
There are two estates of bungalows near me, all built together, all with traditional system boilers with tanks and cylinder.
It seems to me that either the valve actuators work for many years, or on some properties they need regular replacement to the point I keep them in stock.
There are about 7 properties where they will routinely go through one in 12-18 months, even if I install genuine Honeywell heads.
Of late I've taken to manually operating the valve about 100 times before putting a new head on, and this does seem to on average extend the life of the head to about 2 years.

Does it seem reasonable to conclude that if they are regularly failing the issue is mechanical friction or limited valve travel and the motor is burning out ?
I'm considering if rather than just changing them I should say we'll try one new head and after that get a plumber in to change the whole valve body.

Any thoughts, similar experiences, wisdom?

If mid position valves, then as stated in post #8, if the "last port of call" is the CH then the actuator will stay powered up say all night and probably shorten its life, maybe the properties with the short life span actuators have called for CH later than the HW?. If HW is the last call then the actuator is de energised.

 

[johntheo]

I also wonder in the mid position where pulses of DC voltages keep the valve where required against the spring pressure shortens its life, there must be hundreds of systems with UFH/2 port valves which are energised 24/7 for 9 months of the year, do these have reduced life spans compared to the conventional CH 2 port valves?.