Niggling problems with Halstead combi boiler HW + CH

[coxymfc]

hey, im new here (hello all !), been lurking for about 3 years and finally joined today.


I have a problem with a combi boiler, it is a Halstead Ace High, about 7 years old

CH - when the heating is on, the boiler fires up fine, gets warm fine, but after about 5 minutes of being on it switches off, leaving radiators lukewarm, it then sits for about 10 minutes and repeats the process (it has an internal mechanical clock fitted)

DHW - largely the same problem, if the heating has been on then the first leg of water is red hot (which i understand), but then after that it fluctuates in temperature, however if the tap is opened half way then sufficiant hot water comes through


initially i thought perhaps the small thermisto's may have gone, apparently the hot water has always been like this, but the CH has only recently started doing it, i was considering changing both of them on the grounds that the DHW went ages ago, and only recently the CH one has gone, but im wondering if it could be anything else. does anyone have any suggestions or remedies for me, thank you in advance

 

[Agile]

The DHW sounds like a blocked plate heat exchanger.

The CH sounds as if it could simply be the boiler has not been range rated correctly when installed.

But I am guessing that the boiler being a cheap one was not carefully installed and commissioned and has never been properly serviced.

But these settings are gas related and need a competent registered engineer.

Tony Glazier

 

[coxymfc]

The DHW sounds like a blocked plate heat exchanger.

The CH sounds as if it could simply be the boiler has not been range rated correctly when installed.

But I am guessing that the boiler being a cheap one was not carefully installed and commissioned and has never been properly serviced.

But these settings are gas related and need a competent registered engineer.

Tony Glazier

well, judging by the bloke that owns the house, i can pretty much guaruntee its A) never been serviced, and B) he has gone for the cheapest option when buying the boiler, i shall percivere with costs and speak to him about it

 

[Agile]

Now you tell us you are a tenant !

If you are paying a market rent then you deserve a properly working boiler ( even if its a cheap one ).

But do you have a Gas Safety certificate? Thats required by law every year!

Tony

 

[BlueMoonMole]

The thermistors are 10kOHM

Part number Halstead 500-590.

They work in series, so COULD be the cause.

Check the resistances first... if not you'll need a gas engineer

 

[coxymfc]

Now you tell us you are a tenant !

If you are paying a market rent then you deserve a properly working boiler ( even if its a cheap one ).

But do you have a Gas Safety certificate? Thats required by law every year!

Tony

sorry, nah im not a tenant, it was a question asked to me by a friend - "the bloke who owns the house" is my friend, he merely asked me to have a scout around and see if i could have any ideas on what was up with the boiler, he is going to ring a gas safe engineer to do the repair but didnt want to have his pants pulled down (not literally) over the price if it was something simple