Help with vaillant 937 install

[BigBurner]

Screwfix sell pressure gauges.
Time filling a bucket in litres/minute.
Change the stoptap to a full bores tap.
Have a 22mm dedicated cold fee from stop tap to the combi.
The gas supply needs a dedicated 28mm supply from the meter. The length of the run can be determined by this:
http://www.copperinfo.co.uk/webcasts/domestic-gas-pipework-pipe-sizing/player.html

Also for high flowrates look at:
W-Bosch 550, floor mounted job.
Ethos 54C

Fit a magnaclean filter on the CH return pipe, put in X-100 after a good flush and add more every 4 years.

Thank you very much,
what typical pressure would i need and flow rate to keep the boiler working to its capacity. Will i need a pump if it is low?

You can't pump a main pipe. If the flow is too low an accumulator cylinder can be fitted. But do the checks before we go down that rote. 25 litres/min is around what you need. The chance of two baths being filled at once is remote, but two showers is far higher. 25 litres/min will do two showers.

The only reason i decided to go with vaillant is because i know the name, and a lot of people swear by it, i to be honest have never heard of ethos, obviously this is due to my lack of knowledge, i do try to do as much research as poss and did read on this forum about the ethos it sounds very good but i am just worried on reliability etc? would you say that is a better boiler? how much do they roughly cost? and also bearing in mind cost of living these days i dont want to go over board with the boiler i.e. consume vast amounts of gas.

The Ethos is better than the Vaillant and about the same price or cheaper. It has built in weather compensation - just buy the outside temperature sensor. The Vaillant does not have this as standard. The flow rate of the 937 is poor compared to the 550 and Ethos 54C. The 937 only has a 15 litres tank and then reverts to 15 litres/min. The Ethos is Dutch. Vaillant are overrated and overpriced for what they are. They are not the best at all. Look at the W-Bosch 550. Expensive but v good.

A bigger boiler does not mean you burner more gas, the controls take over. The weather compensations means you burn less gas.

vaillant 37kW, 15l/min but can do upto i think 20? using the tanks and blending, £1200
ethos 54c, 41kW, 25l/min, ?
W-Bosch 550 30.6kW, 25l/min, £1800

so is the bosch the best unit seems like it would consume less gas but give similar flow rate to that of the ethos? my cousin has a W-B and swears by it!

The ethos' weather compensation will ensure it is more economical. However the W-Bosch is common so this may put you at rest.

which would you say would be a better all round unit efficiency etc?

The Ethos with weather compensation activated.

The reason i thought 28mm is because i read on the forum for runs 3m or more that is recommended, my run is going to be close to 5m with roughly 6 bends.

Use the sizing calculator I linked to.

Thank you very much for help i really appreciate it.

A Pleasure. Unfortunately there are a few abusive lunatics on this this forum who deliberately set out to wreck threads. Some are on this thread now. Do not respond to them. That is what they want. Don't feed them.

 

[gas4you]

Yet another tragedy waiting to be reported in the news, after following BB's dangerous, incompetent and illegal advice on gas installation

You really should get rid of that chip on your shoulder.

You only abuse you are getting is from yourself by making yourself look more and more stupid with each post you give.

I bet when you were a kid it was always 'mum he's pinched my ball'

Don't worry BB, us experienced, qualified and competent gas operatives will not respond to the OP.

We do not want to encourage him or anyone to carry out dangerous operations in his own home, that could endanger life or property, unlike you

 

[gremlin16]

Unfortunately there are a few abusive lunatics on this this forum who deliberately set out to wreck threads. Some are on this thread now. Do not respond to them. That is what they want. Don't feed them.

Thats good advice from BB.

Seen as you are very willing to give advice on gas related issues, you may like to provide OP's with your registration numbers. eg Corgi. Oftec or any other registration bodies that prove your competence.

(ps Diplomas bought over internet are not acceptable.)

If you are unable to prove your competence then your recommendations can only lead to a tragedy, and as happened previously the Mod's should ban you again.