Upgrading Heating - using second-hand?

[wildmandy]

Hi all.
Some time back my old boiler was in trouble, so I got a quote for a new one. As you're probably aware, it's not just a case of a new boiler, but all the accessories as well (TRV's etc.) In the end the cost was prohibitive, so I had the old boiler repaired instead.

Anyhow, now I'm having some renovations done, including removal of the wall on which the boiler hangs. So, I thought now's the time to get the new boiler.

First up is the old "to install a combi or not" question. My current sytem is open vent, and the last heating engineer I spoke to recommended staying with that unless I need the space where the water cylinder is (I don't). But, I am sorely tempted to rip the header out and remove the cylinder and go this route, the main thing stopping me is that I am not sure my showers (two of) are compatible. The are both the "pull-cord" with their own electric pumps. Thoughts?

Secondly, the quote I had was for new everything, save the radiators, which I wanted to re-use. But what is wrong in re-using the other parts such as the pump, water cylinder, 3 port switch, programmer etc?
I can also see the case for renewal using the age argument (my stuff is 20 years old and more), but I'm wondering if all the parts could be replaced by newer, second-hand parts? For example, I have seen a nearly new replacement cylinder for 35 quid and pumps for around 30.

The quote ends by saying "assume loft lagging is a minimum of 100mm." Presumably, I should check this and think about fitting it if this is not the case?

Final question is about TRV's. My radiators appear to be 15mm x 3/4" and all the TRV's I can see are 1/2". I read something about a bush or convertor - can someone elaborate on that. Also, Do I need new lockshields on all radiators too (not sure if I have these already).

Many thanks,
Mandy

 

[Agile]

Radiators can be bushed to 1/2" if necessary.

Depending on the type of cylinder its recommended that its changed with a new boiler but you dont HAVE to but you SHOULD !

Not many installers will be very happy installing second hand bits you find and they will certainly not give you any warranty. I am one of the very few who might fit good quality s/h bits but I would warn you of the consequences.

Most people would recommend keeping a cylinder rather than a combi if you have two showers fed from the cylinder.

Tony

 

[JohnD]

and on insulation, YES!

the cost and effort of extra insulation will be quickly repaid, it is one of the best investments you can make.

100mm is a minimum, 150mm is better and 250mm is the current standard (however you do get diminishing returns with added thickness so if you have, or fit, 150mm, this will bring most of the benefit.

You should also insulate all hot pipes, and use the thick grade for pipes in unheated spaces, like lofts and under ground floors. this is a simple DIY job, but might be dusty. Pipe insulation is sold in stiff plastic foam tubes, with a seam you can pull open to fit them round existing pipes. you can cut it with a breadknife and it tape it into place especially at bends.

If you get a new cylinder, it will be pre-insulated; if not, you can buy a jacket for an old one.

Old cylinders often leak and it is a lot more trouble and extra expense if you have to change one in an emergency.

Pumps wear out so it seems very mean not to fit a new one.

Lockshield valves wear out and leak so this would be an ideal time to fit new ones. If you are thinming of saving money you could learn some DIY plumbing and fit TRVs and lockshields yourself, it might take you a day or two to do all of them and the skills will be useful in future.

Probably the most important thing when fitting a new boiler is to get the system thoroughly clean. Your installer will probably use a powerflush machine. A dirty system may clog your new boiler and will not be covered by guarantee.

I am just a householder.