Heatline Vizo 24 diagnosis makes sense?

[Kelly1990]

Dear all,
I hope you can advise me please.
My tenant has complained of hot water not being consistent (ie a string of cold water shoots through intermittently).
I've had a plumber look at it who has quoted for the following parts to be fitted to a Heatline Vizo 24 to fix it. Please could you help me to confirm it makes sense and that I'm not being taken advantage of!

Plate to plate heat exchanger - £150
Thermistor sensor - £35
Labour - £80
Diagnosis charge - £45

I would really welcome and be appreciative of any advice you could provide as to whether this is reasonable or not.

Many thanks in advance,

Kelly x[/b]

 

[Slugbabydotcom]

Most the time in my experience it's just the HW thermistor. I'd change that first basically because they are cheap and that's usually all that's required.

The Glow worm Betacom C is basically the same boiler with a different front panel so try one of these It's the same article but cheaper.

If there was still evidence of malfunction then I would look into replacing the plate heat exchanger. If I suspected that both parts were at fault then I would turn up with both parts and return the one I didn't use to the suppliers on my next visit.

There's two sides to a plate heat exchanger :- The primary 'boiler water' side and the HW side.
I've never known the HW side to get blocked but if it did it would be with limescale and in a hard water area. In which case I would be suggesting to fit a Combi mate or other limescale protection device.
If the primary water side is blocked then to prevent re-occurence of the event I would be recommending at least a Magnaclean or similar device and perhaps a chemical flush or powerflush.

EDIT:-
I've just had a quick peak at the prices on ebay for the PHE and I can see that £150 is about right for it but again there are plenty on there that are much cheaper. If you do try to save some money this way remember that the installer will not accept responsibility for something that he didn't provide and to beware of pattern parts
Tip:- This one looks genuine to me

Other charges all seem reasonable to me.

 

[Terry lambert]

As above, If you have a mixer shower, get him to check that's not bypassing cold to hot.

It's not hard to find out the cost of parts these days

Edited after aboves edit

I found a plate for less than £100 Inc on first look, £35 for a sensor, I think he needs to get better terms at his merchants or be more honest and up his labour costs

 

[Kelly1990]

Thank you both for your speedy reply. Absolutely fantastic!

 

[Agile]

Well I diagnose the fault AND clean the plate heat exchanger for £136 in my local area.

Most unlikely to need a temp sensor, but £18 if it did.

But what I dont do is to come out free and then quote an over inflated price as that guy has done. I always charge for a diagnosis. Then offer to do the minimum necessary to fix it!

In fact he has listed ALL the parts which MIGHT be causing that problem.

Was he called Steelmason?

Tony

 

[DP]

Tony I can picture Steelmason thanking you for this useful post

 

[Piers1989]

Are they getting any lock out failure on the lights?

The HW thermistor will not be the cause of the problem (or very unlikely) as if it was, you would have a failure light on the front and the hot water would not work. It is just an NTC thermistor so it allows the PCB to see the temperature that its at based on a resistance. test it at room temperature and it should read approx 10-12k ohms.

Personally, i would measure the temperature differential across the primary circuit onto the plate to plate heatexchanger, the difference should be (approx) 15-20 degrees apart. If its towards 30+ then there is a heat transfer problem. I would also make sure that its not passing on the divertor and allowing the heating system to take the heat.
In theory if you have good heat transfer through a plate to plate heatexchanger, the hot water flow temperature should be +/- 5 degrees the same as the primary return.

The fault is most likely the plate to plate heat exchanger...

Piers

 

[Kelly1990]

Please can I communicate my sincere thanks to all of you who have valuably contributed to my post.

Agile, you helped me out before and you were spot on. I have the utmost respect and appreciation for the advice you provide.

Slugbabydotcom,Tterrydoh, Piers1989 - thank you also most sincerely for taking your valuable time to help me out. Absolutely fantastic!

Have a great 2014.

Hopefully my boiler will get sorted out. At least I'll be able to talk the language thanks to you guys.