Not another boiler kettling question

[TallAndy]

Hi all

Looking for a bit of advice. Here's the problem:- we have a Potterton Suprema 50 boiler in a 4 bed house. Someone has told us this boiler is not up to the job for the size of house.
The boiler has always kettled since we moved in 2 years ago. It used to sound like (duh) a kettle coming to the boil, however last year we had a rad fitted in the garage conversion (taking it up to 14 rads in the house). Now I'm sure it's not my imagination but the kettling seems to have got worse and sounds more like a steam train - a kind of chug-a-chug-a noise. Very loud throughout the house. As far as I know the plumber added some kind of Fernox to the system after he finished the job.

I have the pump speed on the highest setting. If I turn it down to the middle setting the kettling isn't as bad but then some rads struggle to get warm (especially when the hot water is on as well).

I've left it too late this year but I'm now hoping to change the boiler in the spring. In the meantime we have to put up with the old one for another winter. I was wondering if there is an "ideal" combination of (say) pump speed and boiler thermostat setting? I never really know what to have the boiler stat set to - I'm worried that too high will guzzle gas and maybe do more harm than good with the kettling? Any other advice?

Thanks in advance

Andy

 

[bengasman]

If you measure all the radiators, and count double rads twice, how many metres do you have?

 

[Agile]

Kettling wastes gas.

Usually kettling LESSENS if you INCREASE pump speed !

Turn off one valve on every rad.

Add sentinel X200 to the system water and heat hot water for a couple of hours.

That should rediuce kettling if its caused by calcium products. You dont even need to take it out.

Open the rads again after 2-3 hours heating just water.

If it helps push my "Thanks" button, if not then tell us more and we will suggest something else.

Tony

 

[D_Hailsham]

Looking for a bit of advice. Here's the problem:- we have a Potterton Suprema 50 boiler in a 4 bed house. Someone has told us this boiler is not up to the job for the size of house.

OK , lets find out what size boiler you need. Use the Boiler Sizing Wizard to find out. This will be useful when you get the new boiler installed

Your boiler can be set to deliver either 11.4kW or 14.7kW. The boiler's data badge should show what the output setting is.

I have the pump speed on the highest setting. If I turn it down to the middle setting the kettling isn't as bad but then some rads struggle to get warm (especially when the hot water is on as well).

The system may need balancing. See How to balance a CH system

I was wondering if there is an "ideal" combination of (say) pump speed and boiler thermostat setting? I never really know what to have the boiler stat set to - I'm worried that too high will guzzle gas and maybe do more harm than good with the kettling?

The pump speed is determined by the physical layout of the system; i.e size and length of pipes, number and size of rads.

As for the boiler thermostat setting, do you have a separate wall mounted room thermostat? If so, you can set the boiler thermostat to max as the room thermostat will take control. if you do not have a room thermostat, you should get one.

Kettling is caused by limescale deposits. Adding Sentinel X200 to the system will reduce this.

 

[bengasman]

Looking for a bit of advice. Here's the problem:- we have a Potterton Suprema 50 boiler in a 4 bed house. Someone has told us this boiler is not up to the job for the size of house.

OK , lets find out what size boiler you need. Use the Boiler Sizing Wizard to find out. This will be useful when you get the new boiler installed

This will be a totally pointless exercise; the "wizard" might come up with a 20 kW result, but if your rads can't dissipate more than 12, it will be a waste of space.

 

[D_Hailsham]

OK , lets find out what size boiler you need. Use the Boiler Sizing Wizard to find out. This will be useful when you get the new boiler installed

This will be a totally pointless exercise; the "wizard" might come up with a 20 kW result, but if your rads can't dissipate more than 12, it will be a waste of space.

Not pointless at all. If it tells the OP he needs a 20kW boiler, but he has only a 12kW boiler and 12kW of rads and he has been wondering why the house did not get warm, he will now know why. The boiler and rads are not large enough. So, when he comes to install his shiny new boiler next spring, he can also up the sizes of his rads to provide the required heat.

Of course if it works out the other way round - 12kW boiler and 20KW radiators - he can take full advantage of this by running his boiler with a lower flow temperature and a wide differential, which will save money on fuel.

 

[bengasman]

OK , lets find out what size boiler you need. Use the Boiler Sizing Wizard to find out. This will be useful when you get the new boiler installed

This will be a totally pointless exercise; the "wizard" might come up with a 20 kW result, but if your rads can't dissipate more than 12, it will be a waste of space.

Not pointless at all. If it tells the OP he needs a 20kW boiler, but he has only a 12kW boiler and 12kW of rads and he has been wondering why the house did not get warm, he will now know why. The boiler and rads are not large enough. So, when he comes to install his shiny new boiler next spring, he can also up the sizes of his rads to provide the required heat.

Of course if it works out the other way round - 12kW boiler and 20KW radiators - he can take full advantage of this by running his boiler with a lower flow temperature and a wide differential, which will save money on fuel.

Did you require these pearls of wisdom from long years of experience, or do they stem from google? Your logic is that of a teacher that tells the kids how to do it, but never actually installed a boiler in his life.

 

[D_Hailsham]

This will be a totally pointless exercise; the "wizard" might come up with a 20 kW result, but if your rads can't dissipate more than 12, it will be a waste of space.

Not pointless at all. If it tells the OP he needs a 20kW boiler, but he has only a 12kW boiler and 12kW of rads and he has been wondering why the house did not get warm, he will now know why. The boiler and rads are not large enough. So, when he comes to install his shiny new boiler next spring, he can also up the sizes of his rads to provide the required heat.

Of course if it works out the other way round - 12kW boiler and 20KW radiators - he can take full advantage of this by running his boiler with a lower flow temperature and a wide differential, which will save money on fuel.

Your logic is that of a teacher that tells the kids how to do it, but never actually installed a boiler in his life.

At least I am logical; your assumption has no logic. You would argue that, if the house has 12kW of rads then that must be correct; so you only need a 12kW boiler. Carts and horses come to mind.

 

[bengasman]

This will be a totally pointless exercise; the "wizard" might come up with a 20 kW result, but if your rads can't dissipate more than 12, it will be a waste of space.

Not pointless at all. If it tells the OP he needs a 20kW boiler, but he has only a 12kW boiler and 12kW of rads and he has been wondering why the house did not get warm, he will now know why. The boiler and rads are not large enough. So, when he comes to install his shiny new boiler next spring, he can also up the sizes of his rads to provide the required heat.

Of course if it works out the other way round - 12kW boiler and 20KW radiators - he can take full advantage of this by running his boiler with a lower flow temperature and a wide differential, which will save money on fuel.

Your logic is that of a teacher that tells the kids how to do it, but never actually installed a boiler in his life.

At least I am logical; your assumption has no logic. You would argue that, if the house has 12kW of rads then that must be correct; so you only need a 12kW boiler. Carts and horses come to mind.

This is how you determine the size of the boiler needed.

If you measure all the radiators, and count double rads twice, how many metres do you have?

 

[D_Hailsham]

This is how you determine the size of the boiler needed.

If you measure all the radiators, and count double rads twice, how many metres do you have?

That assumes that the radiators are correctly sized in the first place; which is another cart and horse.

 

[bengasman]

This is how you determine the size of the boiler needed.

If you measure all the radiators, and count double rads twice, how many metres do you have?

That assumes that the radiators are correctly sized in the first place; which is another cart and horse.

They may or may not be correctly sized, but if you even entertain the idea that customers will change their radiators because your silly program says they should, you have proven that you have no idea about the world outside your computer.

In case you missed it, this is the worst recession in living memory with 7,000,000 people economically inactive and another million to 2 million expected.

 

[D_Hailsham]

They may or may not be correctly sized, but if you even entertain the idea that customers will change their radiators because your silly program says they should, you have proven that you have no idea about the world outside your computer.

1. It's not my silly program
2. It's up to the customer whether he accepts your advice.
3. What do you say to the customer when he complains, a week after you installed the new boiler, that he is still cold and that he thought the new boiler would solve that problem (which, of course, he had not told you about - he just assumed the reason he was cold was down to the old boiler)?

In case you missed it, this is the worst recession in living memory with 7,000,000 people economically inactive and another million to 2 million expected.

That's no excuse for not doing the job properly. In any case, it's the customer who decides how much money he is willing to spend, not the installer.

 

[Agile]

3. What do you say to the customer when he complains, a week after you installed the new boiler, that he is still cold and that he thought the new boiler would solve that problem (which, of course, he had not told you about - he just assumed the reason he was cold was down to the old boiler)?

A competent installer would assess the heating needs and compare that with the installed heating load and advise the customer that the rads are undersized and need upgrading if the house is to be properly heated.

If the customer chooses not to do that then its a simple "I told you so" !

But expressed in a softer way like,

"I pointed that out to you on my quotation, would you like me to upgrade them now?"

Then when they are upgraded the RGI has a further opportunity for a sale of TRVs !

Tony

 

[bengasman]

3. What do you say to the customer when he complains, a week after you installed the new boiler, that he is still cold and that he thought the new boiler would solve that problem (which, of course, he had not told you about - he just assumed the reason he was cold was down to the old boiler)?

Based on my knowledge gained by experience, and training, I can asses whether the rads are the right size for each room a lot better than some bit of software. Did you forget to answer my question about how long you have been an installer, or are you just trying to hide the fact that you should change your name to: D_Google?

In case you missed it, this is the worst recession in living memory with 7,000,000 people economically inactive and another million to 2 million expected.

That's no excuse for not doing the job properly. In any case, it's the customer who decides how much money he is willing to spend, not the installer.

Again, you are showing your ignorance about the subject; unless there is a complaint about a serious lack of heat, AND I ascertain that the rads are too small, it would be utter nonsense to change the rads because some silly program says you should. This where the knowledge and experience come in that you don't have.

You are exactly the same type as those fools that think setting targets for police and NHS without actually having experience in the field, will make the streets safe and the population healthier.

 

[Agile]

Based on my knowledge gained by experience, and training, I can asses whether the rads are the right size for each room a lot better than some bit of software.

Its usually better to do the training first and gain the experience afterwards!

At least thats how doctors do their training and experience, or as they say "practice".

In fact doctors "practice" for the whole of their career! But then they say "practice makes perfect" !

Tony