underfloor heating badly installed

[nickhants]

I have had an extension with wet underfloor heating installed.

I have spent hours bleeding valves and can get it running for 20 mins then it stops once it runs out of hot water.

The manufacturers say that the pump is not giving enough pressure.

Having looked into it the system it has been installed before the pump and so in my view is not getting any pressure at all. There is a pressure guage indicating this. The plumber has had no experience installing this type of heating. He was organised by the builder.

The ceiling was down before the extension was finished (not now). The underfloor heatin flow and return are 5 feet from the boiler, the pump is 50 feet away behild floorboards and 2 brick walls.There is a 2 foot square attick i can crawl into just! to get to stopcocks for the new heating.

I can see 2 options out of this.

1. If i crawl into the attick i could connect it to a radiator line, which incidentally is the first to come on when the heating starts, will there be enough pressure. All the info i have manage to get indicate that the underfloor heating should run on its own circuits, with radiators and heating on separate circuits one at a time.

2 if i install a second pump to the new heating will it overpower the boiler with too much return pressure causing it to shut down. This pump would be on whenever the rooms thermostat was on stealing hot water from whichever was on hot water or central heating.

Any suggestions ?

 

[BLOD]

What make underfloor heating have you got ? - maybe get them round to advise.
From what you've described your set up doesn't sound right. Why isn't your builder getting this sorted for you ?

 

[chris watkins]

I have had an extension with wet underfloor heating installed.

The plumber has had no experience installing this type of heating. He was organised by the builder.

Any suggestions ?

With all due respect you don't seem to know how U/F heating systems work & why should you? You paid a builder / plumber to do that for you so why an't they coming back to sort it out for you ???

 

[stevetheplumber]

it amazes me i so much as leave a towel from the airing cupboard out of place and i get called back others seem to just get paid and go

 

[mountainman]

it amazes me i so much as leave a towel from the airing cupboard out of place and i get called back others seem to just get paid and go

Oddly enough, it seems that an unscrupulous contractor and a naive customer attract each other!

 

[markfxy]

pumps circulate they don't pressurize the system, did the plumber flush the air from the uhf system?

 

[Barry98]

me opinion is get s real professional to come and sort it , by trying to do it your self you make damage the system and have to restart again a pro might be able to save it for you

 

[snowhead]

The U-Floor pipewrok should have it's own pump, not to pressurise but to circulate just around the floor.

The main pump circulates water from the boiler to the U-Floor pump and maniflold.

When you are bleeding the system you are causing circulation, the heating goes off when the water you allowed to circulate goes cold.

It's not circulating around the floor, you need someone who understands U-F to look at it, not a builder.

 

[chris watkins]

Out of interest how much did you pay for this builder with a guy who did not know much about U/F systems ? Let me guess, it was a "good price" wasn't it ?
The old adage applies "pay peanuts - get monkey's" buyer beware !!!!!!!!!!!!!!!

 

[melmos]

The pipework should have been pressurised on the fill and all air purged from the pipes. Pressure should have been held while screed was poured. The pump on the manifold is there to push the water through the underfloor pipes, for your pump to be 50ft away from heating, that means your manifold is that distance away too, seems to me that there hasnt been any planning done on this and "joe" builder and his "plumber" have done a mish mash

 

[Nostrum]

Is this just a length of hep2o and 2 tee pieces? Do you have a manifold? how hot does the pipes/floor get?

 

[nickhants]

You summed it up correctly.

Warmafloor fitted underfloor manifold. Pressurised whilst screed floor put down. For some reason they wouldnt connect to flow and return fitted by plumber.

Plumber finally admitted never done any underfloor heating before. Simple connected to flow and return from boiler. ie it is gravity fed.

Manifold gets hot before pump is turned on, then gets rid of all available hot water but cant get any more.

 

[nickhants]

They wouldnt fit to flow/return as needed to be pressurised whilst floor went down.

 

[melmos]

Was the boiler output checked to see if it could cope with the additional loading of the underfloor heating, also if this company, Warmafloor, actually designed and fitted the pipework, wouldn't it be an idea to contact them as opposed to the builder and his plumber, who have admitted they don't have a clue.

 

[nickhants]

Was the boiler output checked to see if it could cope with the additional loading of the underfloor heating, also if this company, Warmafloor, actually designed and fitted the pipework, wouldn't it be an idea to contact them as opposed to the builder and his plumber, who have admitted they don't have a clue.

It wasnt but only because my neighbour has similar underfloor heating and large extension already installed.

 

[nickhants]

UK Underfloor Heating do a fantastic wiring and plumbing diagram showing how it should be done. I have a Y plan setup with 3 port valve.

Plumber said all he was told was needed flow and return so fitted a gravity fed flow return plumbed into the pipe 6 feet from boiler in a paralel circuit. now having seen the wiring diagram it seems to be a total cockup.

I can get an a mate (who is a plumber and electrician!) to wire in a second pump into the timed thermostat powering the circulating pump of the UFH, to supply the manifold, which will run in Paralel with hot water and central heating of the main system.

He cant answer the big question 'Will this crash the boiler if both systems run at the same time?'

 

[chris watkins]

Honestly mate what you are typing makes no sense at all, there are implications on how the U/F is controlled & linked to the existing control system & boiler under Part L of the building Regulations you need to get somebody who knows what they are doing in to sort it out.
On the plus side Warmafloor are a good company & what they have installed will be correct so it is the external stuff, stop trying to get it sorted yourself & get somebody in.