gas boiler kettling not heating rads and banging

ameee

Hi hope someone could give me a bit of advice.I have never had gas heating before and im having some problems with my boiler in my rented house and Id like to make sure it definatly is a problem before I call landlord and make an eejit of myself we moved in last january and the heating seemed grand though we havnt really had it on much until now only for the water.It has a bar in the hotpress for water or both water and heat.It only seems to heat a few rads.Ive bled them all but it makes no difference,as in if all heaters are on only upstairs heats and we have to turn off upstairs rads to get the heat to go downstairs? the boiler also kettles from time to time and sometimes make loud banging noises which stop if I turn it off and on again.It also knocks on for a few minutes for no reason sometimes like it is burning off excess gas?pressure seems fine I cant find a pump so Im assuming its inside the boiler? The temperature when turned on goes up to 86 then it sounds like it knocks off (think the flame goes out) and goes rapidly down to 30ish then goes back up flame on whooshing noise and repeats this the whole time? So I dont know whats normal whats not if anyone could point me in the right direction so I can make sense to my landlord when I call Thanks oh boiler was brand new when we moved in

heinbloed

The boiler seems to overheat. Read the manual.
The pump might not be working properly, the generated heat not being transported.

DGOBS

Whats the make/model of boiler? (so I can see where and what filters you may have)

Sounds like the heatexchanger/filter/entire system is suffering sludge or scale and the heatexchanger has become partially blocked

Yes, ring the landlord and get an RGI out, the system may need treating (chemical flushing) and the heatexchanger may need replacement, the poor circulation you have really indicates sludge/scale

You will not find much or any in the manual about that, ask someone with experience in heating systems to advise you. If in doubt please ask

ameee

thanks its a vokera mynute 28he I will definitely call my landlord to send someone out so I was just worried that this is normal for gas heating and i was making a fuss out of nothing though the rads barely getting warm cant be right Ive only had storage heating before so I havnt a clue other then bleeding them I dont want to fiddle too much in case I do my harm then good as its not mine to mess around with and being gas im a bit scared of it

heinbloed

The Vokera manual will tell you how to read the fault signals, these are coded.
If you can't find the manual check the Vokera home page, they have it published.

DGOBS

Can you just confirm the model, wasn't aware of a 28HE model, the Mynute HE came in 12/15/20/25/30/35 kw models (just check it's not an SE or a Unica)

HE models have very large passageways in the heatexchanger and aren't prone to sclae/sludge unless it's pretty extreme, if a HE it must be only a few years old too.

Manuals will not give you diagnostic on scale or sludge, you will just find the appliance may cycle on and off pretty quick with wildly fluctuating temperate (as you described) the manuals and boiler display are pretty good at self diagnostic, but alas not everything can be learned from a book! as good dose of practical experience is usually what is needed

What area of the country are you in, what is the water quality like in the area?

The rads are only getting luke warm as the boiler is reaching set temperature so quickly, then cycles off, the anti-short-cycling on the pcb then limits how quickly the boiler can refire when the temperature drops (rapidly in your case) so the boiler never gets a run at heating the system