What is wrong with my system

[Dragonfly]

Hi

Sorry I can't find my original first post which stated the problem I had with a plumber. To update you all he finally admitted fault and came out last week to rectify the pipe work problem.

Im now left with another issue.. Sigh!

He's probably messed up my motorised valve that feeds the hot water which is external fitted as I have a Unvented hot water cylinder and he says that the valve was stuck in the open position which is why I was constantly getting the boiler firing up as it is calling for hot water. He has moved the pin back the closed position and this resolved the issue somewhat.

What I'm getting now is the wireless thermostats on both floors reaching the set temps for eg 18c and the flame icon remains lit all day and does not go off unless I manually turn the stat down by 1 degree. If I leave them at 18c and then check my rads if they are warm or not, they seem to be like warm or even cold as it seems to me that once they originally warmed up to 18c they no longer reheat up to maintain that temp and the stat as I said still shows flame lit and temp at 18c with the boiler firing up every now and then.

This was a issue I never had before.

What's the chances of Both thermostats becoming faulty which are hung on the walls and not something that has ever been tampered with?

Im so confused. Any one know where and what I should be looking at to find the cause.

Thankyou

 

[ShaunCorbs]

Plumber problems - need advice please - UK Plumbers Forums | Plumbing Advice; Plumbers Talk Forum

Hi Everyone This is my first post here and I hope to hear from some of the experienced plumbers or anyone else in general that has had an issue with plumbing. In October 2018 a plumber came to install full central heating and a unventes cylinder which was zoned to two floors (Basement and...

www.plumbersforums.net

Has he adjusted any wiring ?

 

[Dragonfly]

Plumber problems - need advice please - UK Plumbers Forums | Plumbing Advice; Plumbers Talk Forum

Hi Everyone This is my first post here and I hope to hear from some of the experienced plumbers or anyone else in general that has had an issue with plumbing. In October 2018 a plumber came to install full central heating and a unventes cylinder which was zoned to two floors (Basement and...

www.plumbersforums.net

Has he adjusted any wiring ?

He says he hasn't. He has checked the pcb and it is receiving power so has eliminated a faulty pcb

 

[ShaunCorbs]

Boiler should fire up if the stats are calling providing you don’t have a separate timer to control the time on these zones

 

[Dragonfly]

I have a timer which I can set time for hot water and CH but I use that to keep hot water on auto and CH on the ON position and just Control CH from the stats

 

[Dragonfly]

Here as shown in the image below

 

[ShaunCorbs]

Red light for the ch doesn’t look on in the pic on the timer

 

[Dragonfly]

Red light for the ch doesn’t look on in the pic on the timer

Sorry that's a pic taken from a few days ago, just to show you the setup. The red light does turn on when in the on position when it's switch to it

 

[Dragonfly]

The HW valve is to the far right which he says is on its way out as the pin he says is a little loose and moves easily but the moved that to the off position and then when we called for hot water it opened a little to the left but doesn't seem to close to the right again like the ch valve does, but odd that even though it wouldn't move to the right I wasn't getting the intermittent firing up on the boiler. It seems to do it once it has reached the temp within the boiler by what I can make of it

 

[ShaunCorbs]

And then when the stat is calling eg flame does one of the receivers light up green and then the port valve opens etc and boiler and pump are on ?

 

[Dragonfly]

And then when the stat is calling eg flame does one of the receivers light up green and then the port valve opens etc and boiler and pump are on ?

Yes

 

[ShaunCorbs]

In theory it’s working and the rads should get hot

 

[Dragonfly]

Yes

The issue now seems like the temp on stat is reached but flame does not go off on the stat and therfore the boiler wants to fire up every few minutes but I I increase the temp to say 20 from 18c then the boiler remains fired up until the stat shows it has reached 20c and again the flame remains on display at that temp level

 

[ShaunCorbs]

Tbh don’t have a clue then as it sounds like the stats are working

 

[Dragonfly]

Tbh don’t have a clue then as it sounds like the stats are working

Do you think that if I completely turn the HW off from the timer and then run CH on its own to see if the flame goes off as is there even a small chance that the hot water valve is still calling for hot water which is why the boiler fires and cuts off and not warming the rads to the temp and maintaining them on what has been set on the stat? That may be one possibility to maybe find that it is still the HW valve that's the problem.

 

[Dragonfly]

Il do that in the morning and see if that helps then il know for sure it's the HW valve that is the cause of it. Will update again tomorrow as on night shift currently. Thanks for your time and patience. Will update soon. 👍

 

[ShaunCorbs]

No as the hw doesn’t alter the heating stats calling / interface

 

[king of pipes]

You would be better to set some times into the programmer for central heating and check when the Heating is up to temperature to see if the boiler goes off if your on a constant setting you will have a permanent red neon light on the programmer monitoring a call for heat , faulty motorised valves are quite common and it should be simple to diagnose if the micro switch is not making and breaking correctly . Kop

 

[Dragonfly]

You would be better to set some times into the programmer for central heating and check when the Heating is up to temperature to see if the boiler goes off if your on a constant setting you will have a permanent red neon light on the programmer monitoring a call for heat , faulty motorised valves are quite common and it should be simple to diagnose if the micro switch is not making and breaking correctly . Kop

I have baxi engineers coming out tomorrow as boiler has parts and labour warranty cover so will see what they diagnose as the problem and get back on this. Thanks

 

[Deleted member 120897]

Are they Honeywell or clones (thermostat’)?

 

[Dragonfly]

Are they Honeywell or clones (thermostat’)?

Center Thermostats.

 

[Deleted member 120897]

Center Thermostats.

So, essentially a Honeywell clone. The following links may be helpful:

Link 1
Link 2
Link 3

I think I’ve done them right

 

[Chuck]

The issue now seems like the temp on stat is reached but flame does not go off on the stat and therfore the boiler wants to fire up every few minutes but I I increase the temp to say 20 from 18c then the boiler remains fired up until the stat shows it has reached 20c and again the flame remains on display at that temp level

This is a description of what happens with a thermostat that has TPI control. Once the room is up to temperature the thermostat keeps it there by calling for heat with a boiler on/off ratio that matches the time-averaged boiler output to the losses. The flame symbol on the thermostat display won't go out until the room temperature is a degree or so above the set point (the top of the 'proportional band'), e.g. because solar gain is supplying enough heat to the room that the boiler is not needed.

 

[Dragonfly]

So, essentially a Honeywell clone. The following links may be helpful:

Link 1
Link 2
Link 3

I think I’ve done them right

That's helpful.. My issue was on link 1 and you are right it detects 1 degree difference higher or lower before flame goes off. Baxi seemed to find no fault however still replaced my hot water motorised valve as peace of mind.

I do have another issue which I will post a seperate thread on later tonight which even baxi engineer couldn't suss out so will be interesting on opinions from you pros here. Thanks everyone.