Sabre (Vokera) 25HE No Hot Water nor Central Heating working

[tomerol]

Hi Agile, thank you for your advice.

No disrespect to BB and GG who are currently helping me to solve my problem, but I was also wishing/waiting for your comments/advice on my problem too.
I could not help noticing the amount of posts you have send to this forum as I was reading previous posts before I submit my topic/problem.

As you have probably worked out from the info I have sent so far, I must admit, the combi was not installed properly in the first place. (I swear it was not me ).

The pump made by Grundfos and has 3 speed settings. Before I started to temper with speed adjustments, I did check, it was on number 1 speed. So it must be running on number 1 for the past 2 years.

I took your advice and set my pump speed to maximum (III) but the combi still did not fire up. (It cut out this evening as I was doing the washing up, I could not get it going since). I will leave the pump running on III from now on.

Did I cause a damage to combi as it was running on speed I for the past 2 years?

Could this be the cause of my current problem?

I look forward to hear your comments and further advice.

Tom

 

[BingoBongo]

the primary sensor is on the left hand side

keep pump on 3

but if off to william hill to stick £50 on ign board

 

[Agile]

All I was saying is that the pump should be on setting III.

I doubt that is the cause of your problem.

Time does not allow me to look up your boiler manual to check fault indications but no one has confirmed or denied that the red light is not a sensor fault indication but on simple boilers its usually an ignition failure!

Without more time ( which I cannot give for free advice ) to peruse the instructions or being there I am not able to make any further suggestions at the moment.

Measuring sensor resistance with the boiler totally cold is usually a good indication of their integrity.

It seems there are several flue/water leak problems but they may be nothing to do with your fault.

Tony

 

[DP]

OP, there is a perfectly good flowchart in the manual.

To fix a fault one has to be in front of the boiler or else be supplied information for diagnostic evaluation which will hopefully lead to fault rectification. Also helps to know boiler operate sequence (manual explains this in detail)

You are being given information along with usual suspect.

Your boiler will will run the fan when CH or HW is called for. For CH pump will also run, but not for HW. I would have checked these and eliminated these to proceeds to next stage.

When fan runs, air pressure switch operates and signals the controls to open gas valve and apply spark to burner issuing gas mix.

When the burner fires, flame sense checks for successful ignition, and temperature controls kick in to maintain safe temperature operation.

What stage of operation does the boiler hang up on

View numbers mean nothing as it is up to the individual if input is required. Further counter might be incremented by someone active in gas related work, end user or someone like yourself.

Word of caution. Do not change parts without proper thought as doing this could be an expensive exercise. Recapping, check the manual- by all means take advice given by the regulars (who may well be suggesting certain component replacements will fix the defect, which no doubt could) but have been to these boilers where the cause has been none of what is mentioned.

 

[tomerol]

Thank you for all your replies.

I am getting confused now. According to user manual, Solid Red Light fault indicates to NTC Primary Sensor and it is supposed to be fixed (screwed) on the right hand side of the main heat exchanger.

I bought pair of sensors pictured below.

Untitled

• tomerol
• 22 Jun 2009
• 1

I have changed above sensor and it seems that it can only be fixed to right hand side of the main heat exchanger.

Untitled

• tomerol
• 22 Jun 2009
• 1

It seems that above sensor NTC Probe can only be fixed on the top of a component which is almost in front of DHW heat exchanger. I have not changed this sensor yet. Is this secondary sensor that I should best change?


However, none of my sensors has no 8484 as you mentioned in your early posts. I am concerned that I might have bought sensors not correct for my model of Vokera/Sabre as they did not came in sealed plastic packets.

According to your knowledge, are these the right sensors?

Note: I got the combi working again, by playing with speed of the pump as the hot water tap was on.

 

[tomerol]

To DP,

Thank you for taking your time and writing.

I do understand the principle of how the combi boiler or CH systems works.

However, I do not have knowledge and special equipment necessary for checking and eliminating the components in order to diagnose fault like the qualified engineer would have done.

I am 51 year old, jack of all trades master of none type of guy. I have a bit of brain, I am careful and precise. I am learning as I go along.

I fully understand how difficult it may be for you to give advice without actually being in front of my combi.

Therefore, I am trying to give you guys a correct information within my power and with the right advice, I am hoping to fix my combi.

Note: I will not call myself a car mechanic but I did work in motor trade for about 8 years. I can not recall changing "Sensors" on 2 years old car whether it is Italian or German made.

 

[glasgowgas]

Thank you for all your replies.

I am getting confused now. According to user manual, Solid Red Light fault indicates to NTC Primary Sensor and it is supposed to be fixed (screwed) on the right hand side of the main heat exchanger.

I bought pair of sensors pictured below.

Untitled

• tomerol
• 22 Jun 2009
• 1

I have changed above sensor and it seems that it can only be fixed to right hand side of the main heat exchanger.

Untitled

• tomerol
• 22 Jun 2009
• 1

It seems that above sensor NTC Probe can only be fixed on the top of a component which is almost in front of DHW heat exchanger. I have not changed this sensor yet. Is this secondary sensor that I should best change?


However, none of my sensors has no 8484 as you mentioned in your early posts. I am concerned that I might have bought sensors not correct for my model of Vokera/Sabre as they did not came in sealed plastic packets.

According to your knowledge, are these the right sensors?

Note: I got the combi working again, by playing with speed of the pump as the hot water tap was on.

according to your manual
page 34 pos no 521 part number 10027351 DHW NTC

page 35 pos no 520 part number 10027352 CH NTC

when i was quoting you the part no 8484 these are the ntc`s in most older compacts ( mine included ) our local merchant knows what we are asking for even if vokera/sabre change part numbers about!

not sure about top pic showing a part number 100030

maybe if you pm DP he might shed some light on it

pump speed should be on three, cant think of any reason to turn it down tbh

 

[BingoBongo]

the bottom sensor looks like a pushfit held in place with a sirclip

 

[tomerol]

I think I have bought the correct sensors.
After cross referencing part numbers, supplier gave me the two sensors pictured in my previous post. My receipt is below.

Untitled

• tomerol
• 22 Jun 2009
• 1

Here is the bottom half picture of Sabre (Vokera) 25 HE.

Untitled

• tomerol
• 22 Jun 2009
• 1

QUESTIONS:

1- I have already changed NTC sensor attached to, right hand side of main heat exchanger. (High above where I marked "1" in my picture)
Is this the primary sensor?


2- Even though I can not clearly picture it, where I marked "2" in the picture is looking like the only place is my second sensor can go.
Is this the secondary sensor I was advised to change?


3- Where I marked "3" in the picture: Is this the DHW Flow Regulator you want me to remove and put it in dustbin?

 

[BingoBongo]

ok you have a 35 compact which is really a linea

the 24/28 compact are a bit different

1 is the main

2 is the h/w

3 is the flow switch not the flow regulator

i dont think the sensor u have will work for the hw you need a threaded 1 like the main 1 you have changed.

 

[tomerol]

To BB,

I have a SABRE 25 HE.

Here are the sensors I have changed.

Untitled

• tomerol
• 22 Jun 2009
• 1

As we agree, the one on the left is Primary NTC sensor, and the other one is DHW sensor (secondary sensor?) which I have just changed.

If you look at the DHW sensor closely, you will notice the greenish deposits of rust/water contact at the side and top of it.
As it sits directly under where I have found the water leak (when it was v heavily raining the other day), perhaps this sensor was damaged/shorted by water contact?

Since I changed the DHW sensor, combi fired up easily as it should, CH heating works too (pump setting is on number III ).

So, I am keeping my fingers crossed! I will give it a day or two and will post the result.

 

[glasgowgas]

good for you tomerol

fingers crossed post back any positive or negative results

don`t worry about the flow regulator, i meant that you could/should remove it when the combi was drained.

if your hot water flow rate ever diminishes, giving intermittent lock outs or
hot water goes hot/cold/hot/cold this would be the first thing to remove as it is doesn`t cost ya anything and its a quick fix.

best of

ps just checked yer invoice and re my previous post your two part numbers are correct.
its not unknown for vokera to chop and change their part numbers about!!!!!!!!!!

 

[Agile]

Are you sure that it only worked after you had changed the DHW sensor?

According to your interpretation of the fault code it was the primary sensor at fault.

A boiler engineer would have measured the resistances of the sensors before changing anything.

Still its working now.

I would have expected genuine manufacturer's parts to have been in sealed packets !

Tony

 

[glasgowgas]

I would have expected genuine manufacturer's parts to have been in sealed packets !

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[tomerol]

No, as turned on the hot water tap, just before the stage it normaly fires, it cut out again and the solid red light is on.

I am back to square one

To Agile:

- No, it was working (on and off with the fault) before I change the DWH sensor. I guess, the only other thing happened to made it work short while could be to do with emtying and refilling the system? or not? I do not know.

- Even though the plastic packets were finger seal type, I have no doubt they are Genuine Vokera parts. The numbers on the old one matches the numbers of the new ones exept what I gather the date code. There might be a very little possibility that they may belong to different model.

I have a electrical multifunctional test machine, while I got the old NTC primary sensor, could any of you tell me how to test it please?