Vokera Unica He Tacho/Fan Fault

[Hypagen]

I was wondering if anyone may have experienced similar problems to me with this combi boiler (Vokera Unica He).

The boiler has been installed 3 years and has had light use. The boiler is installed in a bedroom and has a flue to an external wall.

Over the past 4-5 weeks I noticed the boiler was becoming more noisy when switched off. The fan sounds like it is running constantly. After a few weeks of this, one day the boiler failed to ignite with the error code stating there was a problem with the Tacho/Fan.

I reset the boiler, set to heating and it started working normally again for about a week then same error code. If I left the boiler set to heating with the thermostat controlling the demand for heating 24/7 (I would set thermostat to low to switch off and turn up when I wanted heat) it seemed to work fine for a couple of weeks until it failed again with the same error code. The error then became more and more frequent to the point where I couldn't get it to fire at all.

It has been off for a week now but I managed to get it to fire today by first getting it to fire and heat hot water then switch it to central heating. Since the error I've never got the boiler to fire when switched to CH I've always had to get the water heating first. It was intermittentently working at first today but is now fully operational I am hoping this means there may not be too much wrong with it.

Any thoughts would be greatly appreciated!

 

[Hypagen]

I usually like vokeras but the unica is a banger in my experience. They've really let themselves down with the unica

That's not really what I want to hear!

 

[Mbear]

That's not really what I want to hear!

Sorry mate, I think most who do repairs would agree.
I went to a 'mynute he' which is pretty much the same boiler internally except it's a heat only boiler. The rubber hose (cheapskate option, i dont understand whats wrong making a pipe in copper these days) had leaked onto the transformer. So the pipe needed replacing along with the transformer. Parts alone came to £120 inc vat, this system had 18 rads above the boiler so the labour costs where very high.

I'm not impressed with them at all

 

[Hypagen]

I've just had a chat with an engineer who is coming to have a look at my boiler at the weekend.

Without looking at the boiler his advice was that it may be best to invest money in a more reliable boiler rather than waste money repairing the Vokera.

As the fan is running constantly he suggested it could be a fault with the PCB?

Would water leaking on the fan cause a short of somekind leading to the fan running constantly?

 

[Hypagen]

Sorry mate, I think most who do repairs would agree.
I'm not impressed with them at all

The engineer I called would agree with you!

 

[SimonJohns]

I've just had a chat with an engineer who is coming to have a look at my boiler at the weekend.

Without looking at the boiler his advice was that it may be best to invest money in a more reliable boiler rather than waste money repairing the Vokera.

As the fan is running constantly he suggested it could be a fault with the PCB?

Would water leaking on the fan cause a short of somekind leading to the fan running constantly?

I would call a different engineer

This one sounds like he hasn't done many breakdowns on modulating fans

 

[Hypagen]

I would call a different engineer

This one sounds like he hasn't done many breakdowns on modulating fans

Hi Simon, thanks for taking an interest again. My heating was on all night enough to warm the place up and then failed again this afternoon. I've not managed to resart it but I should be safe from hypothermia tonight! It's possible I haven't described the unit properly to the engineer. I didn't mention the model just the make. The engineer was recommended by my Dad and his friend so if it all goes wrong I can blame them ha ha!

As you've mentioned modulating...the fan does still modulate and where I initially thought it was noisy it is in fact just running constantly even when there is no demand for hot water or CH.

When I first power the unit up the fan accelerates up quickly then settles down to what I would consider to be a quite a high RPM and sits at that RPM constantly. When a tap is turned on the fan raises in RPM and when the error clicks in the fan revs up then settles down again similar to initial power up. This all seem fairly normal to me (obviously no expert) appart from the constant running.

I don't know how these things work but I assume there is a sensor or switch that is telling the fan it needs to run?

Do you have any thoughts on diagnosis Simon?

 

[SimonJohns]

Hi Simon, thanks for taking an interest again. My heating was on all night enough to warm the place up and then failed again this afternoon. I've not managed to resart it but I should be safe from hypothermia tonight! It's possible I haven't described the unit properly to the engineer. I didn't mention the model just the make. The engineer was recommended by my Dad and his friend so if it all goes wrong I can blame them ha ha!

As you've mentioned modulating...the fan does still modulate and where I initially thought it was noisy it is in fact just running constantly even when there is no demand for hot water or CH.

When I first power the unit up the fan accelerates up quickly then settles down to what I would consider to be a quite a high RPM and sits at that RPM constantly. When a tap is turned on the fan raises in RPM and when the error clicks in the fan revs up then settles down again similar to initial power up. This all seem fairly normal to me (obviously no expert) appart from the constant running.

I don't know how these things work but I assume there is a sensor or switch that is telling the fan it needs to run?

Do you have any thoughts on diagnosis Simon?

Don't really like to say to much. But I would steer away from a pcb

 

[woodsy]

First, i would disagree with your engineers opinion- boiler is a decent boiler for its price range, if a little dear on the spare parts, i've fitted approx 70 with only the two faults i described earlier and service approx half of those fitted. As your not gsr i don't want to speculate much more than already done but a decent engineer or vokeras fixed price repair should sort it and at 3yr old would be worth it.

 

[Hypagen]

Engineer came out on Saturday just to have a look as his tools were left in a customers house (something like that). He thought I may have had a flow chart showing the ignition proceedure but there is nothing in the Vokera documentation. He said that my boiler should ignite when first powered up and that this wasn't happening.

After a while he admitted he had no experience of these boilers and mainly just dealt with installation of Baxi boilers and didn't really do fault finding. He said he would pass my number and the details of the fault on to his mate who was an expert at fault finding. I was told on Saturday morning I would receive a call in the next 4-6 hours...it is now late Monday night and I have yet to hear anything. I have been too busy today to do anything about it.

 

[SimonJohns]

Engineer came out on Saturday just to have a look as his tools were left in a customers house (something like that). He thought I may have had a flow chart showing the ignition proceedure but there is nothing in the Vokera documentation. He said that my boiler should ignite when first powered up and that this wasn't happening.

After a while he admitted he had no experience of these boilers and mainly just dealt with installation of Baxi boilers and didn't really do fault finding. He said he would pass my number and the details of the fault on to his mate who was an expert at fault finding. I was told on Saturday morning I would receive a call in the next 4-6 hours...it is now late Monday night and I have yet to hear anything. I have been too busy today to do anything about it.

why dont you have one of us come around and help

 

[Hypagen]

why dont you have one of us come around and help

Well I definitely think I've given my "Dads mate's" recommendation a fair chance.

I was beginning to wonder where about in Yorkshire Woodsy was from as he seems to know the model very well. Wales would be too far for you to travel.

 

[Hypagen]

I've had another engineer out this morning and a new fan is now on order. The fan is actually starting to make sounds like it it is worn.

The new fan should arrive Friday morning so I'm hoping for heat by Friday afternoon!

 

[SimonJohns]

I've had another engineer out this morning and a new fan is now on order. The fan is actually starting to make sounds like it it is worn.

The new fan should arrive Friday morning so I'm hoping for heat by Friday afternoon!

I'm glad you took the advice. Saved you a pretty penny

 

[Hypagen]

I'm glad you took the advice. Saved you a pretty penny

I could have had heat a week ago if I'd rang this engineer first!

All the comments on here have been useful to pass on to the engineer and I mentioned to both engineers it was not thought to be the PCB!

 

[woodsy]

Glad that you are sorted and that we have been some help