Baxi 105e fluctuating DHW temperature

[harrodsfree]

I've got a 10 year old 105e which switches on and off while running hot water. On for about 30 seconds then off for about 30 seconds. Really awful in the shower. I'd really appreciate some help please.

I replaced the circuit board in June this year (the thing stopped working so I followed the advice in the manual and bought a new board).

I live in a hard water area and I've had one of those limescale inhibitor things fitted with the wires wound around the pipe (which I suspect doesn't actually do anything).

 

[jwturpin]

i've had the exact same prob occur on my baxi 80e twice in the past year, each time a different. Bet its one of them.

1) DHW thermistor knackered, needs replacing
2) DHW heat exchange unit scaled up, doesn't disipate heat efficiently and causes the outflow back to the main heatplate to be too hot, and it then in turn gets heated up hotter than the boler would actually like, and trips out, restarts when its cooled.

i'm no plumber, but problem 1 cost me £45 call out and £5 part + VAT, and problem two cost me £45 call out and £80 part.

problem 2 hapenned after 10 years, but in a soft water area, so you've done well for it to last that long in a hard water area. and those inhibitor things you mention, not worth it!
Hope thats of some use

jon

 

[Agile]

Most likely to be a blocked plate HE.

But thats blocked on the primary side. Hard water is usually irrelevant.

I dont see Warwick as a particularly hard area.

Tony

 

[harrodsfree]

...blocked on the primary side. Hard water is usually irrelevant.

Many thanks indeed for your input. Should I try flushing it or just buy a new one?

I'm in Rugby. Maybe it isn't really hard water but it certainly gives us bits in our tea and gunges up the ends of taps etc.

 

[jwturpin]

...blocked on the primary side. Hard water is usually irrelevant.

Many thanks indeed for your input. Should I try flushing it or just buy a new one?

I'm in Rugby. Maybe it isn't really hard water but it certainly gives us bits in our tea and gunges up the ends of taps etc.

Ahh! Tha wants to live in God's own county, where t'water is lovely n soft. Thes no gunk in our tea!

 

[powell30]

If you know what your doing you could strip it out and clean it but i would replace it AFTER you have sorted the cause out ie why has the primary blocked?? You may need the system cleaning/powerflushing or it will just happen again.......and again......etc etc

 

[harrodsfree]

Ahh! Tha wants to live in God's own county, where t'water is lovely n soft. Thes no gunk in our tea![/quote]


I would dearly love to live there being brought up in that place.

 

[Agile]

I think that I would prefer Warwickshire myself.

The Parade was very busy with well wrapped shoppers this afternoon!

Tony

 

[Andygasman2010]

I replaced the circuit board in June this year

Long shot but... make sure you fitted the temp control knobs in the right orientation.