Potterton Promax 15HE Heat only boiler replacement

[tranceporter]

Hi,

I bought my house last july. Its a property built in 2005 and came with a Potterton Promax 15HE heat only boiler. The boiler had been previously serviced and maintained by British Gas. We switched suppliers when we bought the house so we do not have any "maintenance scheme" to speak of for the boiler.
2 months ago, the boiler stopped working. It would start intermittently and you could hear the water sloshing from heat exchanger, but the fan would not come on. The guy who tried to repair it tried replacing the pump and ignition PCB but that did not solve the issue. Every time he disconnected and reconnected the flow switch, the boiler would come alive. Then it would stay on for an hour or so before tripping again. Rinse repeat. So I got another guy to look at it, and he took voltage reading, changed the flow switch and topped up the gas pressure. The boiler worked fine for a month. Now we have a weird issue. If we request heat via the thermostat, it fires up, heats the house fine and shuts down. However if we request hot water, half the time it switches on but no ignition/fan, and at other times the ignition/fan come on, it ticks over for 30 minutes and switches off, even if the thermostat requests hot water for 2 hours (I have Salus IT500 thermostat).
The gas engineer who replaced the flow switch is suggesting that rather than replace part by part (the boiler works fine when he comes around to have a look, as usual :skep: ), we can get a new 24/26 kW heat only boiler for 600-70 quid and have it fitted.
So my question is, what heat only boiler of that size would you recommend? Here are my preferences:

1. I would prefer to have as easy a swap as possible from Potterton Promax 15HE. That way I will hopefully not have to pay for replacing the entire pipework and other bits. The gas engineer is recommending Ideal, Vaillant, Alpha, Baxi in that order.
2. The boiler is located in a cupboard in the kitchen. I would prefer the new boiler to be of similar size and not buy a floor standing variant please.
3. I had a read on the forum, and people do not seem to recommend Vaillant for heat only. So what would be recommend make and model taking the above point into consideration?
4. I am leaning towards buying the boiler online and having it fitted (unless you guys recommend me otherwise). However that means by gas engineer will not guarantee the product, understandably. So which manufacturers have relatively hassle-free after sales support?

Lastly, I have a 4 bed semi detached town house with 2 bathrooms with showers, and about 12 radiators.
And thank you for reading I must say I was quite impressed with the quality of information on this website.

 

[walterwhite]

Don't do it on the cheap! It will cost you more in the long run. I always recommend modernising the system by sealing it...ideally this means a system boiler

 

[ShaunCorbs]

the question are you happy with the set up as is, if you are just change the boiler i would suggest viessmann very good boilers

 

[tranceporter]

Thanks. Out of curiosity, why is swapping to another heat only boiler cheap? Are they significantly cheaper that system boilers? Or do you mean that system boilers are much better than heat only boilers and so swapping for another heat only boiler would be cutting corners?

 

[tranceporter]

the question are you happy with the set up as is, if you are just change the boiler i would suggest viessmann very good boilers

Yes, the current water pressure in the shower is fine. House heats up quite nicely when the boiler works. That's why I am considering a straight swap. I do not have much knowledge about boilers, so I cannot tell you where the pump is located for my Potterton Would you say that Veissmann would be an easy straight swap?

 

[ShaunCorbs]

Thanks. Out of curiosity, why is swapping to another heat only boiler cheap? Are they significantly cheaper that system boilers? Or do you mean that system boilers are much better than heat only boilers and so swapping for another heat only boiler would be cutting corners?

more pipework and new cylinder but in return you will get mains pressure hot water

 

[ShaunCorbs]

Yes, the current water pressure in the shower is fine. House heats up quite nicely when the boiler works. That's why I am considering a straight swap. I do not have much knowledge about boilers, so I cannot tell you where the pump is located for my Potterton Would you say that Veissmann would be an easy straight swap?

the pump should be in the airing cupboard with the cylinder and without seeing it i cant say

 

[tranceporter]

That makes sense. When the first repair guy worked on the boiler and tried to replace the pump, he literally sat on the ground swapping the pump in the airing cupboard. So the boiler is on ground floor in a kitchen cabinet, whereas the airing cupboard is next to en-suite on first floor. So you assumption about the pump being situated close to the ground in the airing cupboard is correct if memory serves me right. Going with that assumption, would the swap to Veissmann be relatively straightforward? What about flue pipes etc? Any particular Veissmann boiler you recommend? By the looks of it, the only condensing gas fired wall hung boilers which is open vent (since I am not going for system ones) is Vitodens 100-W open vent. They seem to make a 26kW variant of that model. Is this a good model?

Thanks

 

[ShaunCorbs]

That makes sense. When the first repair guy worked on the boiler and tried to replace the pump, he literally sat on the ground swapping the pump in the airing cupboard. So the boiler is on ground floor in a kitchen cabinet, whereas the airing cupboard is next to en-suite on first floor. So you assumption about the pump being situated close to the ground in the airing cupboard is correct if memory serves me right. Going with that assumption, would the swap to Veissmann be relatively straightforward? What about flue pipes etc? Any particular Veissmann boiler you recommend? By the looks of it, all of their condensing gas fired wall hung boilers are 35kW...



Thanks

like i said before without seeing it i cant comment, but you wont need anything near 35kw your old boiler is about 60000 btu if i remember right which is about 17kw so anything from 20-24kw is fine

fitted a few of these great little boilers

http://www.viessmann.co.uk/en/detac...ondensing_boilers/vitodens_100-w_compact.html

 

[tranceporter]

Haha. Just edited my original post because I found they make 26kW variant lol. Apologies. Since I am an idiot, do new boilers ship with flue kits of do they need to ordered separately? I have attached a pic of pipe which comes out from top of the boiler (I am assuming that's flue pipe).
Also attached a pic of the airing cupboard. Maybe this gives a bit more info? :biggrin:

 

[ShaunCorbs]

Haha. Just edited my original post because I found they make 26kW variant lol. Apologies. Since I am an idiot, do new boilers ship with flue kits of do they need to ordered separately? I have attached a pic of pipe which comes out from top of the boiler (I am assuming that's flue pipe).
Also attached a pic of the airing cupboard. Maybe this gives a bit more info? :biggrin:

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your heating engineer will supply all that so you wont need to know that, the boiler i linked is an open vented boiler which can be converted to a sealed system by the use of an expansion vessel safety valve, and looks an ok job to change

 

[tranceporter]

That's great. Seems like Veissmann 100-W open vent Compact Heat only boiler is the way forward

 

[ShaunCorbs]

That's great. Seems like Veissmann 100-W open vent Compact Heat only boiler is the way forward

upto your installer tho mate as some stick to one or two brands

 

[tranceporter]

I asked my installer about Veissmann and he said they are very good and very expensive. If we take the expensive bit out of the equation since I am willing to pay, that only leaves me with the "very good" bit
That being said, Plumbnation are selling that boiler for £847 delivered, which is the lowest I can find. Seems like a good price.

 

[kris]

When it comes to heat only boilers I'm not so worried about brands, more what's the state of the current pipe work , on a personal level I prefer system boilers but there are many who don't, the change from one to another is simple n usually cheap enough and does away with the f n e tank in attic,

 

[ShaunCorbs]

I asked my installer about Veissmann and he said they are very good and very expensive. If we take the expensive bit out of the equation since I am willing to pay, that only leaves me with the "very good" bit
That being said, Plumbnation are selling that boiler for £847 delivered, which is the lowest I can find. Seems like a good price.

i would speak to your installer before you order and double check you have all the bits you need just in-case he needs something else, nothing worse than waiting for parts

 

[ShaunCorbs]

When it comes to heat only boilers I'm not so worried about brands, more what's the state of the current pipe work , on a personal level I prefer system boilers but there are many who don't, the change from one to another is simple n usually cheap enough and does away with the f n e tank in attic,

sealed system mate

 

[walterwhite]

I'm with those that say 'sealed system'. You're about to spend money & keep an antiquated system. I look forward to your posts in 18 months...

 

[ShaunCorbs]

I'm with those that say 'sealed system'. You're about to spend money & keep an antiquated system. I look forward to your posts in 18 months...

it is a sealed system thats in, read the whole conv

 

[kris]

sealed system mate

What u mean. I'm just stating my opinion regardless of the op's system

 

[ShaunCorbs]

What u mean. I'm just stating my opinion regardless of the op's system

yea i was just saying just in-case you missed it np

 

[kris]

it is a sealed system thats in, read the whole conv

It's not a sealed system

 

[ShaunCorbs]

It's not a sealed system

whats the the expansion vessel and filling loop on the system then?

 

[walterwhite]

Apologies....just seen pic of megaflow & ch exp vess. Sealed system it is!

 

[walterwhite]

OP was referring to open vented, hence confusion...

 

[tranceporter]

Seems like I am misinformed then. I thought I had an open vented system because I have a pipe sticking out if my house where the steam comes out lol. Am I correct in assuming that I need to order viesmann 100-w compact heat only boiler and not system boiler? The link that Shaun posted above was for an open vent viessmann as well.
Or are we saying that I have a sealed system with a Potterton heat only boiler? This is confusing lol. I need to know if j should buy viessmann 100-w open vent heat only or system boiler please

 

[ShaunCorbs]

Seems like I am misinformed then. I thought I had an open vented system because I have a pipe sticking out if my house where the steam comes out lol. Am I correct in assuming that I need to order viesmann 100-w compact heat only boiler and not system boiler? Please confirm

thats the flue i think your talking about, same loc as the boiler?

 

[tranceporter]

thats the flue i think your talking about, same loc as the boiler?

Ah my bad. Must be the flue lol. So do I need to get 100-w system or heat only please? When you shared the link for the viessmann you installed I thought you meant I should install the same one lol. Can you please post a link of the 26kW 100-w model that I should consider? Fit some reason I cannot post links to website

 

[ShaunCorbs]

Ah my bad. Must be the flue lol. So do I need to get 100-w system or heat only please? When you shared the link for the viessmann you installed I thought you meant I should install the same one lol. Can you please post a link of the 26kW 100-w model that I should consider? Fit some reason I cannot post links to website

the link i posted will fit both system if you read it will say

"Whilst being specifically designed for open vent heating systems, the Vitodens 100-W Open vent is suitable for sealed systems using an additional expansion vessel safety valve."

if any worries phone viessmann up they have a nice tech service /advice

 

[tranceporter]

Thanks that makes sense. So if j order the one you linked, then I should also order the valve since my system is sealed. Now it makes sense cheers.

 

[ShaunCorbs]

Thanks that makes sense. So if j order the one you linked, then I should also order the valve since my system is sealed. Now it makes sense cheers.

you should already have the valve, like i have said before if you want to buy the stuff as your installer what he requires if hes good he will make/ write a list of what he requires

 

[tranceporter]

In that case ignore my pm mate. I think I should go to sleep. I have enough jargon for today lol. You have been fantastic help mate. I owe you one

 

[ShaunCorbs]

In that case ignore my pm mate. I think I should go to sleep. I have enough jargon for today lol. You have been fantastic help mate. I owe you one

np and you will see my reply unless gas safe cant go into product detail too much