Hot water calling for heat out of programmed time

[Neel94]

Hi all,

I’ve recently had two viesmann boilers installed on my property which they are randomly firing up to heat my hot water tank out of the hours I have set on the Honeywell programmer.

my plumber tested the zone valve and it’s not sticking, also, on the Honeywell programmer, if I turn it to off, the boilers will shut off, so I’d assume that rules out faulty zone valve?

Also, when I turn down the stat on the hot water tank, that shuts it off.... otherwise the boilers will send heat at random hours of the day to the tank. Even just now at 9:30, I had to turn the stat off directly on the tank as the boilers were running when they are programmed to turn off at 5:30PM.

any help on this would be appreciated.

 

[Donametchi]

Hi all,

I’ve recently had two viesmann boilers installed on my property which they are randomly firing up to heat my hot water tank out of the hours I have set on the Honeywell programmer.

my plumber tested the zone valve and it’s not sticking, also, on the Honeywell programmer, if I turn it to off, the boilers will shut off, so I’d assume that rules out faulty zone valve?

Also, when I turn down the stat on the hot water tank, that shuts it off.. otherwise the boilers will send heat at random hours of the day to the tank. Even just now at 9:30, I had to turn the stat off directly on the tank as the boilers were running when they are programmed to turn off at 5:30PM.

any help on this would be appreciated.

I,m not a fan of the boiler....From what you are saying I,d put it down to a programmer issue

 

[SJB060685]

First are you sure the programmer is set to timed and not constant? As stupid as it sounds first look there. If its set to timed then I'd be checking for stray feed, as above possible programmer

 

[Donametchi]

First are you sure the programmer is set to timed and not constant? As stupid as it sounds first look there. If its set to timed then I'd be checking for stray feed, as above possible programmer

He should not be touching the boiler stat which should be set at 65 degrees.It is a valid point in having the programmer set to constant as this would happen at different intervals throughout the day depending on your hot water draw off.Are you getting sufficient hot water?Is the heating working co insiding with the times allocated?

 

[SJB060685]

He should not be touching the boiler stat which should be set at 65 degrees.It is a valid point in having the programmer set to constant as this would happen at different intervals throughout the day depending on your hot water draw off.Are you getting sufficient hot water?Is the heating working co insiding with the times allocated?

Where did I say about touching the boiler stat?

 

[Neel94]

Hi,
So originally me and my plumber both thought it was the programmer until yesterday, where I changed the programmer for a brand new one. Same issue.

programmer is set to “AUTO”.

i am getting sufficient hot water, never runs out. Also, the heating is working fine, the stats in the house only fire up boilers during the set times where I have increased temperature.
I know it’s the water calling for heat as when I turn off stat on the cylinder hot water tank, The boilers shut down.
Maybe it might be of use that I have two zones for underfloor heating. But I doubt that makes any difference. As they are OFF when the boilers are firing up randomly. My boilers are also set to the 60 degree mark as recommended by my plumber.

 

[Murdoch]

Who wired up these new boilers and controls?

Sounds to me that there could well be a cable in the wrong place... but only somebody with proper kit and knowledge could probably tell you with any certainty

 

[king of pipes]

Have to side with Murdoch on this one get the wiring checked first any pictures ?

 

[Murdoch]

Have to side with Murdoch on this one any pictures ?

Not taking sides but internet diagnosis would be all but impossible

 

[king of pipes]

Not taking sides but internet diagnosis would be all but impossible

Agreed but the first thing to check is the wiring a orange wire in the wrong terminal is all it takes

 

[Neel94]

Hi all,

my plumber is level 3 and I normally trust him on quite a few things... he has a separate sparky to wire up any new installs he does on new boilers installations.
Sparky is coming down Tuesday to have a look. I’ll keep you all posted.
Sparky on the phone also mentioned it still could be a faulty zone valve. Where something is triggering the valve to open making a live connection between boiler and water tank. Is he right in saying this? Trying to suss out sparky as he’s new to me.
[automerge]1587244357[/automerge]
Sorry I must also mention I had a faulty mains valve in the cupboard where the water tank is with all the zone valves. Was minor drips but still, might have dripped onto the Zone valve. Could water damage from the leak be the cause? I would’ve thought the consequences from that would’ve been more severe? Like a completely blown zone valve.

 

[John.g]

Came across something similar but also different a few years ago, the two zone system had been wired with the switched live from the timer/cylinder stat and from the timer/room stat to the zone valve motors had also been wired to where the permanent supply (for the zone valve end switches) should have been wired. Either zone worked fine (on/off) if switched individually but if both were on together then both had to be switched off together because one was back feeding the other.

 

[Neel94]

Came across something similar but also different a few years ago, the two zone system had been wired with the switched live from the timer/cylinder stat and from the timer/room stat to the zone valve motors had also been wired to where the permanent supply (for the zone valve end switches) should have been wired. Either zone worked fine (on/off) if switched individually but if both were on together then both had to be switched off together because one was back feeding the other.

I mentioned something similar to my plumber. That if there’s a possibility that when the boilers fire up for underfloor, it’s somehow opening the zone valve also for the water tank.

 

[king of pipes]

Came across something similar but also different a few years ago, the two zone system had been wired with the switched live from the timer/cylinder stat and from the timer/room stat to the zone valve motors had also been wired to where the permanent supply (for the zone valve end switches) should have been wired. Either zone worked fine (on/off) if switched individually but if both were on together then both had to be switched off together because one was back feeding the other.

I have had it on a two port valve this was a preplumbed cylinder as below , and it's a fairly common fault on a 3 port valve power head when they go bad putting a back feed on , someone who knows there way around a multi meter should be able to track it down . Kop

 

[Murdoch]

Could water damage from the leak be the cause? I would’ve thought the consequences from that would’ve been more severe? Like a completely blown zone valve.

Water ingress into a zone valve is very unlike to “blow” a valve. More like the rcd would trip (very common with carp valves sold these days) or fuse would blow in the fused spur for the boiler

Hope this helps

 

[Neel94]

Water ingress into a zone valve is very unlike to “blow” a valve. More like the rcd would trip (very common with carp valves sold these days) or fuse would blow in the fused spur for the boiler

Hope this helps

Okay well that explains why my fuse spur kept blowing when I had the leak. Was changing it 3/4 times a day.
Maybe this is why I’m having issues with the hot water?

 

[Murdoch]

Okay well that explains why my fuse spur kept blowing when I had the leak. Was changing it 3/4 times a day.
Maybe this is why I’m having issues with the hot water?

When a fuse blows once you change it

When the same fuse blows multiple times - it needs investigating properly