Potterton Puma replacement

jonny2510

Can anyone recommend a cheap combi boiler to replace a Potterton Puma 80?

I'm on a tight budget, so looking for the cheapest I can really.

The house is an 1890s semi (i.e. 100+ years old), with 2 bedrooms, a bathroom (sink, bath, standalone shower run off the combi), living room, dining room and kitchen (all high ish ceilings). There are 6 radiators in total.

Any suggestions?

Myser

For that size house, you could buy a cheap boiler for between £600-£700. Something like an Ideal or Baxi.

keystone

Myser wrote: »

Something like an Ideal or Baxi.

Ideal are carp and Baxi only slightly better. Pay cheap, pay twice. Not very MSE in the round.

OP why do you have to replace it if you are short of readdies?

Cheers

har0ld

My advice, for what it is worth as an unqualified expert, is to always buy German on Combi boilers - slightly dearer initially but do tend to cost less in the long term. Vaillant or Worcester Bosch.
The specs are often a little dubious on the French and Italian ones and my personal view is that they aren't as reliable. British ones I have never been very satisfied with (shame to say).
It all depends on how long you are intending to stay at your property?

Myser

I don't think Worcester Bosch boilers are actually German. Just the company Worcester bought by Bosch.

Viessmann is another good brand.

However, I think the OP is looking for a cheap solution.

david29dpo

Biasi. Four people i know have had one for 5 years now with no problems.

jonny2510

The boiler came with the house, and looks old-ish (I have no idea of it's - though age at least 7 years probably more). The last engineer who came to look at it suggested it would need replacing soon (though it has gone on another 15 months since then!)

The issue is with hot water coming out very slowly upstairs (3 mins to fill the sink, an eternity to fill the bath both at little more than a trickle) and slowly (with some erratic bursts) in the kitchen also. It's usable, but frustrating. Cold water pressure is fine throughout.

Central Heating works fine (albeit it takes a while to heat the cold house - probably not helped by the age of the house and the solid brick walls).

keystone

Was the "last engineer who came to look at it" from BG with his salesmans hat on by any chance?

I think you should devote your resources to getting this one running properly TBH.

This boiler is spec'd to deliver 9.5 litres of hot water / minute at 35 degs C temp rise. What is your HW flow rate? No I don't mean the pressure. Use a bucket and a watch and measure how long it takes in seconds to deliver say 2 or 3 litres. Do the sums to find out the flow rate per minute.

You may have a scaled up heat exchanger slowing everything down. The boiler certainly has an automatic restrictor (I'm guessing of the wax capsule type) which restricts the flow of HW until its up to temp. (I cheated and looked at the installation instructions ).

Now, of course, if the restrictor is knackered then flow rate will be carp as it won't ioperate once the water is up to temp. Equally if the HEX is scaled up but the restrictor is working the water won't get up to temp so the restrictor will keep it at a low flow rate.

Note that it also has a manual flow restrictor on the CW inlet as there is no point in allowing it to deliver a nice high flow rate but only being able to heat it up to 15 or 20 degrees as a result. That goes for any boiler of course.

So - my advice is to get another man in to look at it who knows what he is doing with it and park the idea of a replacement until its BER and you have more cash to spend.

HTH

Cheers

david29dpo

Good point, i am trying to forget about BG!!

jonny2510

keystone wrote: »

Was the "last engineer who came to look at it" from BG with his salesmans hat on by any chance?
[...]
This boiler is spec'd to deliver 9.5 litres of hot water / minute at 35 degs C temp rise. What is your HW flow rate?

Funnily enough he was an "independent", though I suppose he could have just been trying to flog a new boiler.

I did the tests this evening. Once the tap (bath or sink) gets hot, I'm getting 2.1 litres a minute. I've repeated the tests a few times with the same results.

The water did get hot, so I'd expect it not to be a scaled up heat exchanger (please correct me if I'm wrong), though now I think of it, I don't think the rate increased much (if at all) from the initial cold water coming out of the hot tap, to the point where it heated up.

I'd take it from that it's likely it's the wax restrictor (is this the part name???) that needs replacing?

Any ideas on approximate cost for parts/labout that I'd be looking at for this?

Thanks again for your input