Laars Combi Boiler 140 Water Pressure Issue

eengelhart

Hi Everyone,

I’ve recently finished our new home build and have been experiencing issues with water pressure. I’m wondering if there’s more for me to do before calling in outside help. 

Boiler: LAARS Combi Boiler 140

Propane

Heat set to 125*F

Issues: Low water pressure when showering. Water seems hot enough, just feels like more of a heavy rainfall than a shower. 

I’ve adjusted the mixing valve already but I’m wondering if there’s more balancing to be done. Cold water pressure is fine, and sinks have decent hot water pressure. 

It is a 3/4” supply to 1/2” branches. Upstairs shower is the one in question. Also, upstairs sink hot water takes very long to get hot.

Any help is greatly appreciated!

-Evan

hot_rod

There is usually a strainer on the cold inlet, check the manual for how to service it.

eengelhart

https://forum.heatinghelp.com/discussion/comment/1848047#Comment_1848047

yes there is a strainer. I posted this after my attempt to replace the flow restrictor in the cold water inlet for a higher gpm one. Once I got the inlet off, I noticed that there was no “factory installed” lower gpm restrictor, so I did not put the other one in. The unit has only been in use for 4 months, so the strainer was still clean

mattmia2

What is the pressure from the cold water like?

eengelhart

cold water pressure is normal, like any other house so I don’t think it has anything to do with the service to the house

EBEBRATT-Ed

@eengelhart

U really should put a gauge on the hot and cold water where you have access. Fittings are available to put one on a drain valve with a garden hose thread.

hot_rod

shower head, or mixing valve may have debris in it. Disassemble them to see if they are partially plugged

It takes time for the unit to fire and produce hot water, expect a delay, plus the distance matters.

eengelhart

https://forum.heatinghelp.com/discussion/comment/1848058#Comment_1848058

what are the odds that the shower and the sink both have debris on the hot water only? I would post a video showing the difference but I’m not sure how. The sink is very obvious with the difference in hot vs cold pressure

Larry Weingarten

Hi @eengelhart, Do you have good hot water pressure at any other fixtures? If so, the problem is likely not with the heater or nearby plumbing, but at the slow fixtures. I do like the idea of using a gauge to get static pressure, and pressure under different flow conditions.

Yours, Larry

eengelhart

https://forum.heatinghelp.com/discussion/comment/1848063#Comment_1848063

Hi Larry,

Yes I have a kitchen sink on the first floor that seems to have decent hot water pressure. The bathroom with low water pressure is on the second floor.

Jamie Hall

If it's just one fixture, it's something about that fixture or its valves. If it's one group of fixtures, for instance one bathroom group, then check if there is a shutoff valve for that group which isn't all the way open. Not unheard of.

But… if there at least a few fixtures which are acceptable, it's not the combi.