Is combo boiler failing?

Carrot007

Hi,

Just a quick question.

The hot water on my combi boiler has recently only started triggering when the taps are turned quite high.

I have looked around for info but most things just seem to mention in stopping triggering at all.

Is something on the way out?

Cheers.

abankerbutnotafatcat

Firstly, i'm not at all a plumber/central heating engineer so I defer to any advice you get from these types!! However, what I do know is that we've recently moved into a property with a combi boiler and it's my first experience of these babies. We had a few issues such as the radiators on the upper floors not heating so I called over dad!!! He showed me that in the pipework surrounding the boiler there were 2 taps. One was a simple water one which could be used to control the water flow - he suggested I turn it on a little more to help with a problem I was having. The other tap (don't know what it actually is) but by turning on for a few minutes and then turning off again I could increase the water pressure - apparently, mine was too low (below 1, there's a dial on the boiler) which was why the rads weren't heating in the upper floors. A few weeks later I noted that the water pressure had dropped again so I turned the tap again, let the pressure rise and turned it off. Might be worth checking these out - I don't think it can hurt to get familiar with the basic workings of things and one might just work. Good luck :-)

gas4you

We need to know the make and model of your combi before anything definitive can be posted to help you.

Saying that, if it is an older combi with a diaphragm operated HW system, then I would suspect the diaphragm needs replacing.

Carrot007

It is a Jaguar. (Which was a Plumb Center "own brand", Glowworm/Vaillant)

It was fitted in 2002, and has has no problems until now. (Well actually it was dead on install but after that was fixed, no issues).

Not to sure which model (size) it is, but I'm sure it was not the smallest.

gas4you

Firstly check your system pressure is around 1.2 Bar.

I would then want to replace the diaphragm, or at least check it.

It is housed in the front of the 'differential valve' assembly.

mttylad

I had this problem once or twice (different houses different boilers) both times it was the diaghragm.

Although the part itself may only cost a tenner - getting it fitted will cost a lot more.

pineapple

It seems I am the only person in the world who hates these things. The sales pitch says you always have hot water and 'you only pay for what you need'. Well 'scuse me but if I had a water meter I wouldn't dream of having one. Depending on where you are in the house in relation to your combi, you may have to run the water for an age before the water gets hot. I like to rinse my dishes under clean hot water so I have to keep the tap running and the boiler fired up. It can take an age to run a bath and they are prone to erratic behaviour. Give me the old fashioned system of heating the water in a well lagged tank.

Johnhowell

pineapple wrote: »

It seems I am the only person in the world who hates these things. The sales pitch says you always have hot water and 'you only pay for what you need'. Well 'scuse me but if I had a water meter I wouldn't dream of having one. Depending on where you are in the house in relation to your combi, you may have to run the water for an age before the water gets hot. I like to rinse my dishes under clean hot water so I have to keep the tap running and the boiler fired up. It can take an age to run a bath and they are prone to erratic behaviour. Give me the old fashioned system of heating the water in a well lagged tank.

Pineapple - No you are not alone. Sadly, I have to look into renting soon, so will probably have to live with a combi.

John

Lgas

Not a combi fan either! Love my promax+megaflow setup I agree with the other posters, my first thought was the diaphragm.

Only worked on one Jaguar and it caused me a lot of grief!