Baxi 105HE tap water not as hot as it was....?

[plumbingnoob]

Hi,
Quick query, had a Baxi 105HE installed November '05, and it has run very well and performed perfectly adequately.
However, in the last few days the hot water from the taps is not as hot as it was. Used to be able to get really hot water (at times the water almost looked white as it came out the tap) but in the last few days the water seems be around 'very warm' to the lower end of hot.
There is definitely a noticeable difference and while it is manageable at the moment I am wondering if this is a simple maintenance issue, or the portent of worse things to come and a degenerative fault
There are no outward signs of fault, all the lights which should come on do, have the Taps temperature setting to max and Rads to about the 6 o'clock position, and the C/H and rads work as well as ever.
No apparent leaks, flue working OK and pressure at about 2 bar when running. We are in a hard water area. There is a Thermostatic shower working off it upstairs which seems ok temperature wise. There is also an electric shower on the same floor as the boiler running off the cold water feed. Seems ok although flow seems a little lower. The boiler had inhibitor etc when it was installed.
Anything else I could check or is it back to the Yellow Pages and the wallet??

Many thanks in advance.

 

[baxpoti]

Does the C/H flow pipe get hot, when just hot water demanded?

 

[plumbingnoob]

Does the C/H flow pipe get hot, when just hot water demanded?

No, just tried it and only one of the smaller bore pipes gets hot when the hot tap is running. I'm presuming that smaller pipe is the one that feeds the taps. All the others are cold or at least, not hot.

I read in one of the threads about cold water getting into the hot water flow - didnt really understand it, but is that a possibility?

 

[baxpoti]

We are in a hard water area

Oh dear! Plate heat exchanger scaling up?

Thermostatic shower working off it upstairs which seems ok temperature wise

You can under certain circumstances get blended hot/cold water at the delivery point.
Measure the temp at the boiler (dhw out) and then again at the hot tap.

 

[plumbingnoob]

Heh, unfortunately I have no facility to measure Temperatures at specific points, just wondered if there was a simple remedy. Should I try a reset?

So, 1. should I just call an engy and
2. look to get some sort of water softener fitted - Actually live in a 'slightly hard to moderately hard' water area. Is 14 months enough for an exchanger to scale up?

When it comes to choosing an engineer, what should I be looking for apart from CORGI reg - is there a list of recommendations for each area in the country as I' sure there are both good and bad.
Don't particularly want the installer back as they were miserable, unhelpful and way overexpensive. Sry, three questions in one post here.

 

[baxpoti]

You/a competent person needs to carry out further tests to pinpoint the problem, if you have no water softener, you will have problems at some time, this may not be the problem at the moment

You still need to measure

Cold temp in and hot temp out at 12lt/min, measured at boiler.

The gas should stay on full rate 12mb with user dial set on max.

 

[plumbingnoob]

You/a competent person needs to carry out further tests to pinpoint the problem, if you have no water softener, you will have problems at some time, this may not be the problem at the moment

You still need to measure

Cold temp in and hot temp out at 12lt/min, measured at boiler.

The gas should stay on full rate 12mb with user dial set on max.

That'll be the competent person then, as I wouldn't know how to do that.

Have also started to look into those electronic water softener things:

http://www.waterimp.co.uk/waterimps.html
http://www.emwc.uk.com/Details.asp?ProductID=86

as they may help in the long run.
Are there any opinions on these??ie Do they actually work.
Don't want to start getting into the softeners that add sodium etc.

 

[plumbingnoob]

Decided to err on the side of caution and book a Corgi engineer for next Thursday.
Will post any diagnosis in the event it might help anyone in the future.

Also going to ask about supply/install of a Combimate unless I'm told they are a complete waste of time.

Thanks for help

 

[Agile]

Limescale is not any problem in most areas when a modern boiler is operating correctly as the DHW does not get hot enough to deposit scale.

I would suggest a magnetic type if you must waste your money on one.

I expect you are just expecting too much when the cold is coming in at about 6°C. Try reducing the flow rate at the tap!

Tony

 

[kevplumb]

I would suggest a magnetic type if you must waste your money on one

try them up here the water eats them for breakfast

 

[plumbingnoob]

Up here = Newcastle area so Kevplumb probably has an idea of the water type as he's from down the road.
If it is the exchanger scaled up I'll probably go for one because any scale will have accumulated in only 15 months.

 

[Agile]

I have only once seen a plate HEX with scale and that was just a tiny film but not affecting performance.

That was in Bracknel where the water is very hard.

I have been to lots of boilers in Reading where its pretty hard and its no problem at all there.

It all depends on the boiler controling its temperature properly and the primary being clean.

Tony

 

[ChrisR]

Your water mains may have got colder. You should get 10 litres /minute at showering temperature though.
ALso try: starting from all cold, put HW tap on and see if the CH flow pipe gets hot

 

[plumbingnoob]

Update: (if it helps others) -

Engineer attended, fully checked boiler inc. diverter valve, gas pressure, measured flow and temperatures etc etc, gave it a service and cleaned burners etc etc.
Stated there was nothing wrong and all was in working order. Stated that in this area a combimate or electronic/magnetic descalers were not necessary and if the exchanger did scale up eventually then a replacement was only about £40 so it would be cheaper just to replace the exchanger if it ever did scale up.
Said it was probably just a drop in water mains temp.
So, at least my mind is at rest and there are apparently no problems.
Oh, and it cost £40 so it was worth it.
However, having used the system again, it is now back up to the hightemperatures it was before - strange eh? Maybe a service was just the trick, bit of a clean is needed now and again.

Thanks for all suggestions.