New boiler.

[kevinlightfoot]

It is time we had a new boiler,the boiler at present is working but we had troubles last year.It is the type of boiler that you have to pressurise and if the pressure drops for any reason the boiler will not work.It runs nineteen radiators and gives us domestic hot water,some radiators get hot some don't,my old house was also quite large and the heating engineer put in a double Grundfoss pump(two pumps side by side) I think I may need this.I want to have a boiler fitted with a proper header tank installed and a proper thermostat where you don't have to keep moving it to different parts of the house and the whole house keeps warm.My question is what are the chances of a heating engineer being able to do this and the system being efficient and reliable and by efficient I do not mean fitting money saving gadgets that do not work.All I want is to be able to switch the heating on using a timed device and the house,the whole house to get warm.Any comments or advice would be gratefully received,regards Kevin.

 

[Gerry]

From what you say you will have the same issues with a new boiler!

It sounds to me like you need to balance your radiators so they all heat up and use the thermostatic radiator valves to control the room temperatures. The thermostat goes in the main living area which should not have a thermostatic radiator valve fitted.

Depending on the age of the system and if you have any additives in it you may need to flush the crap out of the radiators too.

Gerry

 

[AES]

I'm far from knowledgeable here, but one thing we do have (as well as all the rest of the gubbins inside) is an outside thermostat. It seems these are common in Switzerland and part of the initial installation though (1997 in our case) but I'd not heard of it before. It's mounted under the (well set back) eaves to the garage door and is set (if I remember correctly) to 15 deg C. Being well out of the wind and weather the idea is that the heating (nothing to do with hot water which is independent of that thermostat) will only run when the ambient temps get below that setting. Dunno if that sort of thing applies in UK though.

 

[sunnybob]

AES... I think theres something wrong there. youre talking about a frost thermostat where it activates when the temp goes below the setting. But that would mean the inside of your house will only be heated once the outside temp goes below 15 c? Which means if its 16 outside, then its 16 inside.
I wouldnt want to live there.
Kevin, 19 radiators? I had a 5 bed house that only had 12.
It sounds like your plumbing needs a complete rip out and start again. With that amount of rads you need a manifold for each floor for flow and return. Then you could fit thermostatic valves to all but the towel rails, and adjust each room seperately to get the desired temp you need.
Its gonna be costly. :shock: :shock: :shock:

 

[deema]

The poor heating engineer will be set a difficult task. It sounds like an older property which has no doubt been tinkered with by people of varying degrees of knowledge and capability. There are many reasons why radiators don’t heat up whilst others do...some causes....
The pipe runs haven’t been balanced properly
There is gunk / sediment build up in the pipes / radiators.
You have air in the system / radiators causing an air lock
The pump hasn’t been set to the right pressure.
The pipes are not lagged properly and the water is cooling down on the run to the affected radiators.
Additional radiators have been spurred off reducing flow
Pipes have become kinked

Clearly if your willing to have it completely replumbed there is absolutely no reason why you can’t have what your asking for. I personally would prefer a system that doesn’t have a header tank.......you see too many celings that have collapsed due to the ball value failing (normally the ball leaks and fills with water) causing the header to overflow. Or better still install the tank sat on top of MDF or Ply that’s not WBP and the whole thing arriving in a bedroom one evening as the Soggy MDF / Ply gives way

 

[Marineboy]

Yes, you don’t want a header tank. Outdated technology.

 

[mbartlett99]

Hi Kevin

Its difficult to give advice where there are so many possibilities for issues to exist (some of which have been touched upon already) and as usual more information would be necessary. With that said, your post reads strangely:
1) Is this house new to you?
2) If not are have these issues always existed ie rads not heating, pressure loss on system?
3) Most users are going from a traditional (header tank) boiler to combi boiler (pressurised) not the other way - sounds like your boiler is relatively new?
4)You have a moveable themostat - again thats a relatively new thing. You don't have to move it - leave it in the hallway.
So, from your post it doesn't seem like you have an old knackered system, although that doesn't mean it was designed properly of course.

Might I suggest, before spending a lot of money needlessly, that you sort your issues first and then decide;
1) The rads that don't heat - have you bled them of air? Its quick and its free.
2) Do they have thermostatic valves - not expensive to retrofit and no matter what you do in the future its a good step.
3) If the system pressure changes regularly consider installng an accumulator - to smooth out the differences.
4) If the plumbing is older have it flushed so you're getting best performance out of your existing install.

Fitting two pumps sounds like a bodge. To put that in perspective the vessel I'm working right now has 3 circulating loops of different types, would translate to a massive house and each loop has one fairly small grundfos pump doing the work. Have you bled the pump, is it making a noise (like air trapped in it)?

Anyway, thats my tuppence, hope you have some success.

 

[kevinlightfoot]

Thanks for everyone's input,the heating engineer is supposed to be calling me tonight to discuss,yes we are fairly new to the house and yes it is a large place.Its the second time I have heard that the system needs balancing maybe so I may just get that job done first.The boiler is eleven years old so I would rather get that renewed than risk future breakdowns.I will post to let you know the outcomes of my discussions with my heating engineer and again thanks for your suggestions,regards Kevin.

 

[RobinBHM]

Although not that well known, boilers made by intergas are reckoned to be very made. Wheras Bosch are not -they now spend their money on marketing whilst cost cutting on components. Maybe something to consider.

Its worth asking about boiler makes and configurations on diynot forum -its frequented by a lot of heating engineers

 

[jimmy_s]

Most domestic boilers are only suitable for systems without header tanks. Your choice will be limited if you want to go open vented - not very common nowdays.

By the sounds of things you are looking for a weather compensated system where the boiler modulates the flow temperaure depending on outside temperature.

If you have some radiators that are not heating it could be air (tops will be cold) sludge or poor balancing. If its sludge you can drain the system and take the affected rads out / take the valves off them and run a hose pipe through them - or get a power flush, works better if pipework is not minibore/ microbore.
If its a balancing issue then you could start closing the lockshield valves down on the radiaors that are hotter to improve the flow to the cooler ones - best to do it with the Thermostatic Rad Valve heads off (if fitted)

Twin head pumps are fairly common on commercial and industrial heating systems but not really needed. As far as I know we are one of the few countries that do this apart from N. America and Canada where a pump failure could be a lot more problematic.

I like Viessmann boilers and use a lot of them and am fairly familiar with the controls etc.

Finding a heating engineer - I would think that's going to be a bit of a lottery.

 

[tsb]

If you have a problem with the pressure dropping on your boiler and cutting out, you've either got a leak on your system somewhere ( it only needs to be a minute leak) or another problem with your system is the size. In your boiler you will have an expansion vessel and I'll guarantee it will be too small for the amount of water in your system.(19 rads) Putting another external vessel in your system will help.
New regs came into play last year for new boilers- check out "boiler plus" This includes fitting a weather compensated system