Gas boiler query .....

barry attack

HI guys , I live in an apartment and have a Sime system format gas boiler , which is used to heat water for baths etc and for heating rads .
Since I moved in in 2006 ,when i want to heat the rads the boiler starts up as normal and continue to run until I turn it off , but when I turn temp down on the thermostat in the hall just to heat the water for a shower , the boiler will start and stop in a cycle i.e fan turns on , gas ignites , lights for about 15 - 20 seconds and then stops for approx 5 seconds and then it starts again .
This does heat the water and not the rads but seems very labour intensive while just heating water ,... that the boiler should start and stop continually like this .
It takes about 25 mins to heat water for a shower .

Wild_Dogger

The appliance of science bud ........

Have ye checked the head-gasket ????????

heinbloed

Is the DHW heated via a heat exchanger - maybe in a thermally insulated tank? Or is it a combi-boiler ?
What is described as

.... lights for about 15 - 20 seconds and then stops for approx 5 seconds and then it starts again .

sounds like very bad plumbing. Something fiddled together without thinking, planning. The heat exchanger is to small to give-off the heat from the central heating boiler to the surrounding domestic water. Therefore the boiler senses quickly a high return temperature and switches off.

A typical situation where the boiler is over-dimensioned.

The boiler's output could be decreased, the pump set higher(faster). But this is only a hint, get a real plumber in to optimise the system.

barry attack

barry attack wrote: »

HI guys , I live in an apartment and have a Sime system format gas boiler , which is used to heat water for baths etc and for heating rads .
Since I moved in in 2006 ,when i want to heat the rads the boiler starts up as normal and continue to run until I turn it off , but when I turn temp down on the thermostat in the hall just to heat the water for a shower , the boiler will start and stop in a cycle i.e fan turns on , gas ignites , lights for about 15 - 20 seconds and then stops for approx 5 seconds and then it starts again .
This does heat the water and not the rads but seems very labour intensive while just heating water ,... that the boiler should start and stop continually like this .
It takes about 25 mins to heat water for a shower .

The hot water circuit is smaller than your heating circuit, so the boiler achieves temperature quicker, it might be worthwhile when you have the boiler serviced to ask the RGI if there is anyway to improve circulation around the hot water circuit.

barry attack

heinbloed wrote: »

Is the DHW heated via a heat exchanger - maybe in a thermally insulated tank?

I have an insulated copper tank in the hot press .
So I presume this is a " thermally insulated tank.
Did ask a plumber about it before and he just said that was the way it is , but that cant be right .
Needless to say , I didnt get him back !

Would an adjustment on the boiler be sufficient ? or do I need actual plumbing work done ?

Thanks for the replies !;)

slavetothegrind

try opening up the valve on the coil return on the cylinder, if no trv or zone valve is on the hw piping it could just be choked too much?

heinbloed

Barry attack asks:

Would an adjustment on the boiler be sufficient ? or do I need actual plumbing work done ?

It really depends on the system's lay-out, the boiler type ect..

Most boilers can be reduced in their output, the older ones are more simple to do. But it is always the job of a heating engineer. Important parameters have to be checked after this job, before comissioning it. Get a signed protocoll/report from the professional, otherwise your system is without insurance by all means.

It could be enough to adjust the parameters within their already certified limits. For example increasing the flow, spreading the difference between flow and return temperature. Maybe their is a faulty valve, a sludged-up pipe ect..

Try to get hold of the boiler manufacturer's manual as well as the manual from the tank manufacturer.
If the parameters (heat production boiler versus heat usage heatexchanger) don't match and can't be brought to one level then the heating system can't work efficient.
If the system had been designed by a legal person as it is and doesn't work efficient then you (as a consumer) have a right to get replacement. You can also charge the designer for financial losses.

barry attack

Thanks for the reply , so there's definately something wrong with the system . this is obviously not the way it should be .
They were built in 2004 and I know an occupant underneath us got a new boiler because his system wasn't fitted correctly
So maybe I'll get an engineer to asses the situation .
the neighbours have the same problem with thiers too .

Perhaps I might be covered by some kind of guarantee if the system is in fact fitted incorectly , but its going to require a lot of chasing to pursue

Any advice ?

Thanks again !

heinbloed

There should be a register, a list of comissioned installations with Board Gais (or whoever supplies the connection to your meter). There you'll find the installer.

barry attack

barry attack wrote: »

Thanks for the reply , so there's definately something wrong with the system . this is obviously not the way it should be .

You have hot water, you have heating, no damage is being done to the boiler.

heinbloed

Gary71 wrote:

You have hot water, you have heating, no damage is being done to the boiler.

The OP has no demaged boiler but an inefficient heating system.

This is against building regulations, a system operating as described is inefficient. And with this complaint the seller/installer has to be confronted. It is up to the installer to proof that his heating installation is conform with Irish regulations as well as with EU standards concerning operation safety and operating economical. Legislations/guidelines concerning enviromental protection, for example EG2005/32 come on top of this.

And inefficient heating systems aren't allowed anymore to be installed, with small exemptions like for example protected structures or when technicall or economical non-rational.Since many years.

My advise to the OP is to get a heating engineer in who will measssure the efficiency and write a report.
If the efficiency of the system (or any other required point) was never able to meet the legislations at the time the wrong heating system was installed. And has to be replaced.


B.t.w., is it a condensing boiler?

mightymouse311

on cylinder the heting return pipe should have a throttling vavle on it usually a red handled wheel valve open it up 2 or 3 turns sounds like the flow rate out of the boiler is to slow for the heat output of the boiler This could take away heat from your rads when the two are on together but i dont think it will try it and see what happens

barry attack

hi

its not a condensing boiler,and tried the valve ,reckon i'll get someone in to have alook and see what the story is...........thanks for replys